CURRICULUM VITAE
Name:
Edward L. Grabczyk
Business Address:
Department of Genetics
Louisiana State University Health Sciences Center
533 Bolivar Street
New Orleans, LA 70112
Business Telephone and Telefax:
(504) 568-6154, (504) 568-8500
Business email Address:
egrabc@lsuhsc.edu
Citizenship:
USA
Education:
Undergraduate
B.S., University of California at Los Angeles
1982, Psychology-Biology (Magna Cum Laude)
Graduate/Medical
Ph.D., Harvard University
1992, Cell and Developmental Biology
Post-Doctoral Fellowships
1992-1995
Post-Doctoral Fellow
Cardiovascular Research Center
Massachusetts General Hospital
1995-2000
Intramural Research Training Award Fellow
Laboratory of Molecular and Cellular Biology
NIDDK, National Institutes of Health
Academic, Professional, and Research Appointments:
2000-2001
Staff Fellow
Laboratory of Molecular and Cellular Biology
NIDDK, National Institutes of Health
2001-2008
Assistant Professor
Department of Genetics
Louisiana State University Health Sciences Center
2008-present Associate Professor
Department of Genetics
Louisiana State University Health Sciences Center
Edward L. Grabczyk
CV p. 2
Membership in Professional Organizations:
2001-present American Association for the Advancement of Science
2002-present American Society for Biochemistry & Molecular Biology
2002-2004
American Society of Human Genetics
2003-2004
Society for Neuroscience
Awards and Honors: (include sabbaticals)
none
Teaching Experience/Responsibilities:
Course/Clerkship/Residency or Fellowship/CME Directorships
NA
Curriculum Development/Implementation
In each of the last six years I taught classes in the practical use of current
bioinformatics tools for graduate students in "Basic Human Genetics" (LSUHSC
Genet 231) and in "Cell and Molecular Biology" (LSUHSC Bioch 240, CMB-A,
and CMB-B). In introductory courses this usually takes the form of lectures
introducing the students to some of the better websites for bio-information such
as NCBI and the UCSC genome browser. However, I find a hands-on approach
works best for bioinformatics. When possible, I give assignments that require the
use of multiple on-line tools. Discussing the best or quickest route to good
information can draw in even the quietest students, and provides a good segue
to search strategy optimization.
The use, and the importance of computer aided analysis of biological information
is increasing daily. There is a real need for a formal course in bioinformatics for
the graduate students at LSUHSC. Therefore, I designed and implemented a
new course at the LSUHSC school of graduate studies called Practical
Bioinformatics (GENET 256). I have designed this course to be an in-depth
analysis of both the theory and use of bioinformatic tools, emphasizing extensive
hands-on use by the students.
Creation of Enduring Teaching Materials
Due to the rapidly evolving nature of bioinformatics (and to avoid teaching
"history of bioinformatics"), fresh material must be assembled each year.
Consequently, preparation for teaching GENET 256 is much more time-intensive
than lecture preparation for courses in mature or static areas of science.
However, the extra preparation must be done, because staying on top of the
latest technology is essential to the core value of this course.
Formal Course Responsibilities
2002-2005
Lecturer, "Basic Human Genetics"
Graduate LSUHSC GENET 231
In each year I presented 2-3 lecture hours on the use of current
bioinformatic tools in the service of genetic research.
2002-2004
Lecturer, "Molecular Structure and Function of the Cell"
Graduate LSUHSC PHYS 251.
Edward L. Grabczyk
CV p. 3
In each year I presented 3 lecture hours covering DNA Replication
and repair, DNA recombination, and regulation of transcription in
eukaryotes.
2005
Lecturer, "Molecular Biology"
Graduate LSUHSC BIOCH 240
I presented detailed lectures from replication origin recognition to
termination of replication in ten lecture hours. I also introduced
the students to recent papers in the primary literature on these
topics. I used papers that illuminate a mechanism particularly
well, or are on either side of a dispute to stimulate discussion.
I also presented 2 lecture hours on the use of bioinformatic tools
in biochemistry.
2005
Lecturer, "Cell and Molecular Biology, (CMB-B) Molecular Genetic
Mechanisms"
Graduate LSUHSC INTER 122
I presented 5 lecture hours on DNA Replication, covering
initiation, termination and regulation.
2006
Lecturer, "Cell and Molecular Biology, (CMB-C) Control of Gene
Expression"
Graduate LSUHSC INTER 123
I presented 2 lecture hours on the use of current bioinformatic
tools in the analysis of gene expression.
2006
Lecturer, "Cell and Molecular Biology, (CMB-A) Cell Biology"
Graduate LSUHSC INTER 121
I presented 1 lecture hour introducing current bioinformatic tools.
2006
Lecturer, "Cell and Molecular Biology, (CMB-B) Molecular Genetic
Mechanisms"
Graduate LSUHSC INTER 122
I presented 10 lecture hours on DNA Replication, including
mechanistic details of initiation, termination and regulation.
Lecturer, "Cell and Molecular Biology, (CMB-B) Molecular Genetic
Mechanisms"
Graduate LSUHSC INTER 122
I presented 5 lecture hours on DNA Replication and site-specific
recombination.
Lecturer, "Cell and Molecular Biology, (CMB-C) Control of Gene
Expression"
Graduate LSUHSC INTER 123
I presented 5 lecture hours on the use of current bioinformatic
tools in the analysis of gene expression.
Course Director, "Practical Bioinformatics"
Graduate LSUHSC GENET 256
I presented 42 lecture hours on the practical use of bioinformatic
tools in biological research. This course introduces graduate
students to the use of a variety of bioinformatic tools. Students
used the tools to analyze different types of data.
2007
2008
2008
Edward L. Grabczyk
2008
2009
CV p. 4
Lecturer, "Cell and Molecular Biology, (CMB-B) Molecular Genetic
Mechanisms"
Graduate LSUHSC INTER 122
I presented 5 lecture hours on DNA Replication and site-specific
recombination.
Lecturer, "Cell and Molecular Biology, (CMB-C) Control of Gene
Expression"
Graduate LSUHSC INTER 123
I presented 5 lecture hours on the use of current bioinformatic
tools in the analysis of gene expression
Departmental/Interdisciplinary conferences
2001-2004
I have also taught an informal course on practical molecular
biology laboratory techniques. I designed the course primarily to
teach molecular techniques, including theory and trouble-shooting,
needed by students who might enter my own lab. Although aimed
at first and second year Genetics graduate students, others joined
as they heard that it was a useful seminar series.
Special Clinical Rounds – Chairman’s Rounds, Chief’s Conference, etc
NA
Teaching Awards:
none
Graduate Students Trained:
M. Sammarco
2001-2005
Ph.D. Conferred 5/2005
Thesis Title: "The Iron Chef: Today's Mystery Ingredient, Frataxin"
M. Mancuso
2001-2006
Ph.D. Conferred 12/2006
Thesis Title: "Interruptions in the GAA•TTC Repeat of Friedreich Ataxia Alleviate
DNA Triplex Formation"
A. Banerjee
2004-present
S. Ditch
2005-present
A. Sidhu
2005
Thesis and Dissertation Committees:
D. Arnaud Winnier
2002-2004
rotation student
Genetics
Ph.D. Conferred 5/2004
Post-Doctoral Fellows Trained:
M. Sammarco, Ph.D. 2005-present
Currently Dr. Sammarco is working on the transcriptional deficit caused by the
FRDA repeat, and on iron dysregulation caused by reduced frataxin.
M. Mancuso, Ph.D.
2006-2007
Edward L. Grabczyk
CV p. 5
Dr. Mancuso stayed for several months after the Ph.D. to finish work that was
delayed by hurricane Katrina. Currently Dr. Mancuso is working as a postdoctoral fellow with David H. Martin, MD, in the Department of Microbiology,
Immunology & Parasitology at LSUHSC, New Orleans.
Undergraduate Students:
Jeffrey Wang
Jeffrey Wang
Summer 2007*
Summer 2008*
Summer Student from Emory
Summer Student from Emory
*Over-all winner of the year-end poster competition for summer interns 2007 and 2008
Edward L. Grabczyk
CV p. 6
Grants and Contracts:
Funded
Principal Investigator:
Edward L. Grabczyk, Ph.D.
"Mechanisms contributing to frataxin deficiency"
Agency:
National Institutes of Health
Type:
R01 (1R01NS046567-01A2)
Direct Costs: $636,088
Period:
September 1, 2005 to July 31, 2009
Description: The long-term objective of this project is to alleviate the frataxin
insufficiency that causes Friedreich ataxia, the most common inherited ataxia.
Principal Investigator:
Edward L. Grabczyk, Ph.D.
"Mechanisms contributing to frataxin deficiency"
Agency:
National Institutes of Health
Type:
NIH Administrative Supplement to grant 1RO1NSO46567-01A2.
ARRA summer supplement
Total Costs: $9,728
Period:
Fiscal year, 2009-2010
Description: In response to NOT-OD-09-060: Recovery Act Administrative
Supplement to Provide Summer Research Experiences for Undergraduate
Students.
Principal Investigator:
Edward L. Grabczyk, Ph.D.
"Mechanisms contributing to frataxin deficiency"
Agency:
National Institutes of Health
Type:
NIH Administrative Supplement to grant 1RO1NSO46567-01A2.
(3R01NS046567-03S1)
Total Costs: $10,000
Period:
Fiscal year, 2008
Description: In response to NOT-NS-08-009: "Administrative Supplements for
High-Quality Low-Cost Monoclonal Antibodies for Studies of the Nervous
System"
Principal Investigator:
Edward L. Grabczyk, Ph.D.
"Katrina Supplement"
Agency:
Friedreich’s Ataxia Research Alliance
Type:
FARA Supplemental Research Grant
Direct Costs: $40,000
Period:
June 1, 2006 to May 31, 2007
Description: Supplemental Research Grant is to help re-establish Friedreich
ataxia research projects that were lost due to the effects of a natural disaster,
Hurricane Katrina.
Principal Investigator:
Edward L. Grabczyk, Ph.D.
"Comparative analysis of expanded triplet repeat sequences from Friedreich
ataxia patients of Acadian and non-Acadian heritage"
Agency:
Friedreich’s Ataxia Research Alliance and
the Muscular Dystrophy Association
Type:
FARA/MDA Research Grant
Edward L. Grabczyk
CV p. 7
Direct Costs: $88,300
Period:
July 1, 2002 to June 30, 2005
Description: The long-term objective of this project is to determine if the milder
course of the Acadian form of Friedreich ataxia correlates to specific differences
found in the sequence of Acadian FRDA repeats.
Principal Investigator:
Edward L. Grabczyk, Ph.D.
"A tandem reporter system to test the efficacy of agents that improve
transcription through GAA•TTC tracts in human cells"
Agency:
Friedreich’s Ataxia Research Alliance
Type: FARA Research Grant
Direct Costs: $25,000
Period: March 15, 2001 to August 15, 2001
Description: The long-term objective of this project is to investigate ways to
alleviate the reduction in frataxin gene expression caused by expanded
GAA•TTC trinucleotide tracts in Friedreich's ataxia.
Pending applications
2009 NIH Recovery Act Administrative Supplement to grant 1RO1NSO46567.
The total funds requested are: $76,743
Non-funded applications (last three years)
2009 NIH R03
PI
"Subcellular translocation of Iron Regulatory
Protein 2 in a disease model"
2008 National Ataxia Foundation PI
"The contribution of IRP2 to
neurodegeneration in FRDA and the potential for therapeutic intervention"
2008 NIH R03
PI
"ROS damage in iron-loaded cells: mechanism,
time frame and effect of oxygen" Resubmission
2008 NIH NRSA F31
Sponsor
"The role of DNA repair in
trinucleotide repeat instability" Resubmission
2007 NIH R03
PI
"ROS damage in iron-loaded cells: mechanism,
time frame and effect of oxygen"
2007 W. F. Keck Foundation
PI
"Illuminating the Contribution of
Nucleotide Excision Repair to DNA Repeat Instability"
2007 NIH NRSA F31
Sponsor
trinucleotide repeat instability"
"The role of DNA repair in
Research Review Committee: (NIH study section, etc)
Friedreich’s Ataxia Research Alliance: Ad Hoc reviewer
Ataxia UK: Ad Hoc reviewer
Edward L. Grabczyk
CV p. 8
Inventions and Patents:
none
Seminars and Invited Presentations:
2/2003 "A persistent RNA•DNA hybrid in the Friedreich ataxia triplet repeat is
formed by transcription in vivo"
International Friedreich’s Ataxia
Research Conference, Bethesda, MD
4/2003 "Mutations with a Twist: Friedreich Ataxia"
Tulane University, New Orleans, LA
8/2003 "Trinucleotide Repeat Disorders" in Genomics: Solving the DNA puzzle A Workshop for Teachers, LSUHSC, New Orleans, LA
10/2004 "What Can Friedreich Ataxia Teach Us About Aging?"
National Institute on Aging Workshop "The Role of Chromatin Structure &
Genome Stability in Aging & Senescence" New Orleans, LA
4/2005 "Tactics to Beat Friedreich Ataxia."
Gene Therapy Seminar Series, LSUHSC, New Orleans, LA
5/2006 "DNA Repeats, DNA Structures and Genome Instability"
Stanley S. Scott Cancer Center Retreat, New Orleans
11/2006 "Integrated Dual Reporters to Measure Repression of Transcription
Elongation by FRDA Repeats in Human Cells" International Friedreich's
Ataxia Scientific Conference, Bethesda, MD
11/2006 "Structure formation, UV damage and DNA repeat instability" Tulane
University Cancer Center, New Orleans, LA
5/2007 "DNA Repeat Instability: Seeking Clues to Carcinogenesis"
Stanley S. Scott Cancer Center, New Orleans, LA.
Editorial Posts and Activities:
Journal editorships or associate editorships
NA
Reviewer status
Analytical Biochemistry:
Genomics:
Neuroscience Letters:
Nucleic Acids Research:
Ad Hoc Reviewer
Reviewer
Ad Hoc Reviewer
Ad Hoc Reviewer
University/Institutional Service:
Departmental committees
2002-2007
Faculty Recruitment Committee
2002-2008
Graduate Admission Committee
2004-2008
Graduate Qualifying Exam Committee
Genetics
Genetics
Genetics
School of Medicine committees LSUHSC (New Orleans)
2002-2004
Core Labs Steering Committee
2003-2005
Research Space Advisory Committee
2006-present Institutional Biosafety Committee
Hospital committees
NA
Edward L. Grabczyk
CV p. 9
Professional society committees
none
Special assignments – ad hoc task forces/working groups, projects, etc
2006-present Emergency Response Team Member
LSUHSC
Member of both the "Lock-Down Team" and the "Go Team"
Clinical Service: (may elaborate details further on portfolio)
NA
Administrative Responsibilities: (must include some narrative description)
NA
Community Service Activities:
Friedreich’s Ataxia Research Alliance (FARA) Fundraising and Awareness
activities. In March of 2007 we coordinated a Friedreich ataxia awareness event
with FARA, the Louisiana chapter of the National Ataxia Foundation and Kyle
Bryant. Kyle has FRDA, he rode a modified bicycle across the country to raise
money and awareness for FRDA. He came to our lab to see the work we were
doing. We gave a tour of the lab, and the department of Genetics to Kyle,
members of his family, FARA, NAF and the press as well (for details, see the
March 10th, 2007 article in the New Orleans Times-Picayune).
Louisiana Society for the Prevention of Cruelty to Animals (LASPCA) Supporter:
In 2007 we raised over $800 for the LASPCA
Books:
none
Book Chapters:
none
Videos and Multimedia:
none
Scientific Exhibits:
none
Journal Publications:
Refereed
Federoff, H. J., Grabczyk, E. and Fishman, M. C. (1988) Dual regulation of
GAP-43 gene expression by nerve growth factor and glucocorticoids. J. Biol.
Chem. 263, 19290-19295.
De la Monte, S. M., Federoff, H. J., Ng, S. C., Grabczyk, E. and Fishman, M. C.
(1989) GAP-43 gene expression during development: persistence in a distinctive
set of neurons in the mature central nervous system. Dev. Brain Res. 46, 161168.
Edward L. Grabczyk
CV p. 10
Grabczyk, E., Zuber, M. X., Federoff, H. J., Ng, S.-C., Pack, A. and Fishman, M.
C. (1990) Cloning and characterization of the rat gene encoding GAP-43. Eur. J.
Neurosci. 2, 822-827.
Vanselow, J., Grabczyk, E., Ping, J., Baetscher, M., Teng, S., and Fishman, M.
C. (1994) GAP-43 transgenic mice: Dispersed genomic sequences confer a
GAP-43-like expression pattern during development and regeneration. J.
Neurosci. 14, 499-510
Grabczyk, E. and Fishman, M. C. (1995) A long purine•pyrimidine homopolymer
acts as a transcriptional diode. J. Biol. Chem. 270, 1791-1797
Lavedan, C., Grabczyk, E., Usdin, K., and Nussbaum, R. L. (1998) Long
uninterrupted CGG repeats within the first exon of the human FMR-1 gene are
not intrinsically unstable in transgenic mice. Genomics 50, 229-240
Grabczyk, E. and Usdin, K. (1999) Generation of microgram quantities of
trinucleotide repeat tracts of defined length, interspersion pattern and orientation.
Analytical Biochemistry, 267, 241-243
Grabczyk, E. and Usdin, K. (2000) The GAA•TTC triplet repeat expanded in
Friedreich's ataxia impedes transcription elongation by T7 RNA polymerase in a
length and supercoil dependent manner. Nucleic Acids Research, 28, 28152822
Usdin, K. and Grabczyk, E. (2000) DNA repeat expansions and human disease.
Cellular and Molecular Life Sciences, 57, 914–931
Grabczyk, E. and Usdin, K. (2000) Alleviating transcript insufficiency caused by
Friedreich's ataxia triplet repeats. Nucleic Acids Research, 28, 4930-4937
Grabczyk, E., Kumari, D. and Usdin, K. (2001) Fragile X syndrome and
Friedreich’s ataxia: Two different paradigms for repeat induced transcript
insufficiency. Brain Research Bulletin, 56, 367–373
Sammarco, M. C. and Grabczyk, E. (2005) A series of bidirectional tetracyclineinducible promoters provides coordinated protein expression. Analytical
Biochemistry, 346, 210-216
Entezam, A., Biacsi, R., Orrison, B., Saha, T., Hoffman, G.E., Grabczyk, E.,
Nussbaum, R.L. and Usdin, K. (2007) Regional FMRP deficits and large repeat
expansions into the full mutation range in a new Fragile X premutation mouse
model. Gene, 395, 125-134.
Grabczyk, E., Mancuso, M., and Sammarco, M. C. (2007) A persistent
RNA•DNA hybrid formed by transcription of the Friedreich ataxia triplet repeat in
live bacteria, and by T7 RNAP in vitro. Nucleic Acids Research, 35, 5351-5359.
Sammarco, M. C., Ditch, S., Banerjee, A. and Grabczyk, E. (2008) Ferritin L
and H Subunits Are Differentially Regulated on a Post-transcriptional Level. J.
Biol. Chem., 283, 4578-4587.
Edward L. Grabczyk
CV p. 11
Banerjee*, A., Sammarco*, M. C., Ditch, S., Wang, J. and Grabczyk, E. (2009)
A Novel Tandem Reporter Quantifies RNA Polymerase II Termination in
Mammalian Cells. PLoS ONE (Accepted; submitted May 18, 2009).
Banerjee, A., Sammarco, M. C., Ditch, S., and Grabczyk, E. (2009) A dual
reporter approach to quantify defects in mRNA processing. Analytical
Biochemistry (Submitted June 2, 2009).
Ditch, S., Sammarco, M. C., Banerjee, A. and Grabczyk, E. (2009)
Transcription-dependent GAA•TTC Repeat Expansion in Human Cell Lines.
PLoS Genetics (In revision; submitted Feb. 27, 2009)
Research Interest Narrative
The long-term goal of my research is to develop therapies for degenerative
conditions associated with aging. I currently study the molecular biology and
biochemistry of Friedreich ataxia (FRDA). Although it can strike in childhood,
FRDA has attributes that pertain to other neurodegenerative diseases and to
pathologic conditions of aging: 1) An unstable trinucleotide repeat that can
expand with age. 2) Reduced mitochondrial function and lower Fe•S enzyme
activities such as aconitase. 3) Disrupted iron homeostasis and iron
accumulation in the mitochondria. 4) Increased ROS production in the
mitochondria. 5) Increased sensitivity of Fe•S enzymes to ROS.
FRDA is caused by an unstable GAA•TTC repeat expansion in the first intron of
the FXN gene that reduces frataxin expression. The degree of repression
correlates with the length of the repeat, but it is unclear how transcription is
reduced. Frataxin is a nuclear encoded mitochondrial protein with a role in ironsulfur (Fe•S) cluster assembly. Insufficient frataxin causes mitochondrial
dysfunction, most severely affecting cells with high metabolic rates. The variable
onset of neurodegeneration and cardiomyopathy in FRDA patients stems from a
combination of reduced ATP production and increased ROS damage. One
percent of the population carries an expanded repeat in one FXN allele, making it
the most common triplet expansion known. The GAA•TTC repeat expanded from
an Alu element, suggesting a vast reservoir for other such expansions.
My first several years here were spent building and testing tissue culture systems
to model FRDA. Unfortunately, we lost all these reagents due to Hurricane
Katrina. However, regenerating the models is nearly complete. We currently
have model systems in human cells for different aspects of Friedreich ataxia,
including: transcription impairment by GAA•TTC repeats, repeat instability and
iron dysregulation. I am optimistic that the next few years will be an exciting time
in my lab, as these reagents will produce a wealth of data and publications.
I. Impaired transcription in FRDA. A primary goal in my lab currently is to
understand why GAA•TTC repeats expand, and how the expansion impairs gene
expression in FRDA. We have engineered a series of unique dual reporter
vectors in human cell lines to dissect the mechanism, and to serve as highthroughput tests of candidate FRDA therapies. An active R01 supports this work,
Edward L. Grabczyk
CV p. 12
and we have an agreement with a major pharmaceutical company to collaborate
for a large-scale screen. One series uses a tandem reporter system designed for
the study of transcription elongation. The two luciferase reporters provide a
ratiometric readout that measures the transcriptional impediment presented by
an insert.
A second series features a splicing FXN minigene. The bidirectional promoter
we designed and built (Sammarco and Grabczyk, 2005) can be induced to
provide more local negative supercoiling than a single sided promoter, which
encourages structure formation in the repeat. Our recently published finding that
an RNA•DNA hybrid forms upon transcription of a GAA•TTC tract (Grabczyk, et
al., 2007) has ramifications for both transcription elongation and repeat instability.
Recent work by the Manley and Aguilera groups shows that disruption of cotranscriptional RNP processing leads to RNA•DNA hybrid formation, elongation
defects and genome-wide instability. In addition to being a tool for translational
medicine, our cell lines will also allow us to study how factors such as chromatin
state, transcription and DNA damage influence repeat stability.
II. DNA instability. We have found that the GAA•TTC repeat is remarkably
unstable in human cells in tissue culture. We have documented wholesale and
continuous expansion with time in culture. Most long trinucleotide repeats are
unstable to some degree, and mismatch repair has been implicated in their
continued expansion with age. The TTC template strand in the FRDA repeat is,
in addition, a large target for the formation of pyrimidine dimers by UV irradiation.
We will probe the idea that nucleotide excision repair and/or transcriptioncoupled repair further destabilize the repeat. We will especially look for
interactions with XPD mutants.
Finally, we have shown that a Tn7 transposon will specifically insert into an
FRDA patient derived repeat when conditions encourage Y•R•Y triplex formation.
Once interrupted, the sequence is less prone to form structures. A first paper
describing this data has been submitted (Mancuso, et al., 2008). We will expand
this work on two fronts: 1) As proof of principle that transposable elements can
be used to interrupt long FRDA repeats. 2) We will extend this structured DNA
attraction assay to enzymes involved in chromosomal translocations.
III. Frataxin links metabolism, iron handling and increased ROS sensitivity
to neurodegeneration. Because FRDA shares features with other
neurodegenerative diseases and with conditions of aging, part of my long-term
strategy is to apply the knowledge gained in the study of FRDA to the study of
aging. In a second area of research, we are exploring the relationship between
frataxin expression and iron and oxygen metabolism. Frataxin is a mitochondrial
protein critical to iron-sulfur cluster biosynthesis. Frataxin mediated changes in
iron metabolism are reflected in the activities of iron response proteins, and we
use a custom IRE bearing reporter system we developed to quantify these
changes.
The aerobic function of FRDA cells can resemble aged cells. Insufficient frataxin
slows replacement of Fe•S clusters, which heightens sensitivity to ROS. Slowed
replacement in respiratory complexes I, II and III compromises OXPHOS and
increases ROS. Cytosolic aconitase, in the absence of its Fe•S cluster, becomes
Edward L. Grabczyk
CV p. 13
Iron Regulatory Protein 1 and alters iron metabolism. Oxidative stress from
outside the cell can send this cycle spinning out of control. Understanding how
frataxin modulates iron homeostasis and mitochondrial function should provide
insights helpful to other conditions that lead to similar declines in aerobic function
and increases in ROS. We use lentiviral vectors expressing frataxin cDNA or
shRNA to modulate frataxin in custom iron reporter cell lines, and in FRDA
patient lines. We have found a complex interaction between oxygen tension, iron
levels, frataxin expression and Fe•S status of key players in metabolism such as
aconitase. A paper detailing our initial findings has been published (Sammarco,
et al., 2008) and a follow-up paper is in preparation.
Finally, a decline in Fe•S assembly can also impact the nucleus. In yeast, ROS
generated in the mitochondria has been shown to damage nuclear DNA. In the
large neurons affected in FRDA this direct path for mitochondrial generated ROS
is less likely. We are interested in the possibility that reduced frataxin expression
limits the ability of Fe•S cluster enzymes in the nucleus to perform their functions.
In particular, we will investigate whether the activities of the Fe•S helicases XPD,
BRIP1 and Rtel respond to frataxin levels and experimentally induced ROS. Rtel
helicase has been shown to stabilize telomeres and other asymmetric
purine•pyrimidine sequences. XPD and Rtel may have roles in both GAA•TTC
repeat stability, and chromosomal stability during aging.
Abstracts:
Miriam Martinez, Mimi C. Sammarco, Jason Manning, Ed Grabczyk "Tn7
preferentially inserts into GAA•TTC repeats" American Society for Biochemistry
and Molecular Biology (ASBMB) Annual Meeting, Boston MA, June, 2004.
Mimi C. Sammarco, Miriam Martinez, Jason Manning, Ed Grabczyk
"Quantification of transcription elongation through GAA•TTC repeat tracts using
a novel tandem reporter system" American Society for Biochemistry and
Molecular Biology (ASBMB) Annual Meeting, Boston MA, June, 2004.
*Ayan Banerjee, Scott Ditch, Mimi C. Sammarco, and Ed Grabczyk
"A novel reporter system to investigate the molecular cause of Friedreich Ataxia"
The National Ataxia Foundation, Ataxia Investigator's Meeting, Las Vegas NV,
March, 2008
*National Ataxia Foundation Travel Grant Winner
*Scott Ditch, Ayan Banerjee, Mimi C. Sammarco, and Ed Grabczyk
"A human cellular model of GAA•TTC repeat expansion responsible for
Friedreich ataxia" The National Ataxia Foundation, Ataxia Investigator's Meeting,
Las Vegas NV, March, 2008
*National Ataxia Foundation Travel Grant Winner
Mimi C. Sammarco, Ayan Banerjee, Scott Ditch, and Ed Grabczyk
"Look Closer: Iron homeostasis in model FRDA cells" The National Ataxia
Foundation, Ataxia Investigator's Meeting, Las Vegas NV, March, 2008
Edward L. Grabczyk
CV p. 14
*Mimi C. Sammarco, Scott Ditch, Ayan Banerjee, and Ed Grabczyk
"Ferritin L and H subunits are differentially regulated on a post-transcriptional
level" FASEB J. 22: 998.3, American Society for Biochemistry and Molecular
Biology (ASBMB) Annual Meeting, San Diego CA, April, 2008
*ASBMB Graduate or Postdoctoral Travel Award Winner
*Scott Ditch, Ayan Banerjee, Mimi C. Sammarco, and Ed Grabczyk
"A model of GAA•TTC repeat expansion in human cell lines" FASEB J. 22: 776.1
American Society for Biochemistry and Molecular Biology (ASBMB) Annual
Meeting, San Diego CA, April, 2008
*ASBMB Graduate or Postdoctoral Travel Award Winner
Ayan Banerjee, Scott Ditch, Mimi C. Sammarco, and Ed Grabczyk
"A novel reporter system to investigate the molecular cause of Friedreich Ataxia"
FASEB J. 22: 781.1 American Society for Biochemistry and Molecular Biology
(ASBMB) Annual Meeting, San Diego CA, April, 2008
Mimi C. Sammarco, Scott Ditch, Ayan Banerjee, Jeffrey Wang, and Ed Grabczyk
"Quantitation of transcription termination mediated by actin and hemoglobin
polyadenylation sites using a novel tandem reporter" FASEB J. 22: 781.4
American Society for Biochemistry and Molecular Biology (ASBMB) Annual
Meeting, San Diego CA, April, 2008