Podle hesla „exocyst“ vše od historie až po 31. 12. 2006
Langevin J, Morgan MJ, Sibarita JB, Aresta S, Murthy M, Schwarz T, Camonis J, Bellaiche Y.
Dev Cell. 2005 Sep;9(3):355-76.
Drosophila exocyst components Sec5, Sec6, and Sec15 regulate DE-Cadherin trafficking from
recycling endosomes to the plasma membrane.
Terbush DR, Guo W, Dunkelbarger S, Novick P.
Methods Enzymol. 2001;329:100-10.
Purification and characterization of yeast exocyst complex.
Ponnambalam S, Baldwin SA.
Mol Membr Biol. 2003 Apr-Jun;20(2):129-39.
Constitutive protein secretion from the trans-Golgi network to the plasma membrane.
Wang S, Hsu SC.
Hybrid Hybridomics. 2003 Jun;22(3):159-64.
Immunological characterization of exocyst complex subunits in cell differentiation.
Langevin J, Morgan MJ, Sibarita JB, Aresta S, Murthy M, Schwarz T, Camonis J, Bellaiche Y.
Dev Cell. 2005 Sep;9(3):355-76.
Drosophila exocyst components Sec5, Sec6, and Sec15 regulate DE-Cadherin trafficking from
recycling endosomes to the plasma membrane.
Wang S, Hsu SC.
Biochem Soc Trans. 2006 Nov;34(Pt 5):687-90.
The molecular mechanisms of the mammalian exocyst complex in exocytosis.
Zhang G, Kashimshetty R, Ng KE, Tan HB, Yeong FM.
J Cell Biol. 2006 Jul 17;174(2):207-20.
Exit from mitosis triggers Chs2p transport from the endoplasmic reticulum to mother-daughter
neck via the secretory pathway in budding yeast.
Gerges NZ, Backos DS, Rupasinghe CN, Spaller MR, Esteban JA.
EMBO J. 2006 Apr 19;25(8):1623-34. Epub 2006 Apr 6.
Dual role of the exocyst in AMPA receptor targeting and insertion into the postsynaptic
membrane.
Sivaram MV, Saporita JA, Furgason ML, Boettcher AJ, Munson M.
Dimerization of the exocyst protein Sec6p and its interaction with the t-SNARE Sec9p.
Biochemistry. 2005 Apr 26;44(16):6302-11.
4: Methods Enzymol. 2001;329:100-10.
Purification and characterization of yeast exocyst complex.
Terbush DR, Guo W, Dunkelbarger S, Novick P.
Department of Biochemistry and Molecular Biology, Uniformed Services University
of the Health Sciences, Bethesda, Maryland 20814, USA.
Publication Types:
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
PMID: 11210526 [PubMed - indexed for MEDLINE]
5: Mol Membr Biol. 2003 Apr-Jun;20(2):129-39.
Constitutive protein secretion from the trans-Golgi network to the plasma membrane.
Ponnambalam S, Baldwin SA.
School of Biochemistry and Molecular Biology, University of Leeds, UK.
s.ponnambalam@bmb.leeds.ac.uk
Constitutive secretion is used to deliver newly synthesized proteins to the cell surface and to the
extracellular milieu. The trans-Golgi network is a key station along this route that mediates sorting of
proteins into distinct transport pathways, aided in part by clathrin and adaptor proteins. Subsequent
movement of proteins to the plasma membrane can occur either directly or via the endocytic pathway.
Moreover, multiple, parallel pathways from the trans-Golgi network to the plasma membrane appear to
exist, not only in complex, polarized cells such as epithelial cells and neurons, but also in relatively
simple cells such as fibroblasts. In addition to typical secretory vesicles, these pathways involve both
small, pleiomorphic transport containers and relatively large tubular-saccular carriers that travel along
cytoskeletal tracks. While production and movement of these membranous structures are typically
described as constitutive, recent studies have revealed that these key steps in secretion are tightly
regulated by Ras-superfamily GTPases, members of the protein kinase D family and tethering
complexes such as the exocyst.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 12851070 [PubMed - indexed for MEDLINE]
6: Hybrid Hybridomics. 2003 Jun;22(3):159-64.
Immunological characterization of exocyst complex subunits in cell
differentiation.
Wang S, Hsu SC.
Department of Cell Biology and Neurosciences, Rutgers University, Piscataway, NJ
08854, USA.
We have generated monoclonal antibodies (MAbs) against three proteins sec6, sec15, and exo84.
These proteins have been shown to be components of the exocyst complex, a macromolecule
required for many biological processes such as kidney epithelial formation and neuronal development.
These antibodies can detect the three proteins by enzyme-linked immunoadsorbent assay (ELISA),
Western blotting, immunofluorescence microscopy, and immunoprecipitation. Using these antibodies,
we found that the three proteins have similar subcellular localization which changes upon cell
differentiation. These three proteins also co-immunoprecipitate with each other. These results suggest
that at least three exocyst subunits associate with each other in vivo and redistribute in response to
cell differentiation. In the future, these antibodies should be useful in the cell biological and functional
analysis of the exocyst complex under physiological and pathological conditions.
Publication Types:
Research Support, U.S. Gov't, P.H.S.
PMID: 12954101 [PubMed - indexed for MEDLINE]
2: Dev Cell. 2005 Sep;9(3):355-76.
Drosophila exocyst components Sec5, Sec6, and Sec15 regulate DE-Cadherin trafficking from
recycling endosomes to the plasma membrane.
Langevin J, Morgan MJ, Sibarita JB, Aresta S, Murthy M, Schwarz T, Camonis J, Bellaiche Y.
Polarite Cellulaire chez la drosophile, UMR 144, Paris, France.
The E-Cadherin-catenin complex plays a critical role in epithelial cell-cell adhesion, polarization, and
morphogenesis. Here, we have analyzed the mechanism of Drosophila E-Cadherin (DE-Cad)
localization. Loss of function of the Drosophila exocyst components sec5, sec6, and sec15 in epithelial
cells results in DE-Cad accumulation in an enlarged Rab11 recycling endosomal compartment and
inhibits DE-Cad delivery to the membrane. Furthermore, Rab11 and Armadillo interact with the
exocyst components Sec15 and Sec10, respectively. Our results support a model whereby the
exocyst regulates DE-Cadherin trafficking, from recycling endosomes to sites on the epithelial cell
membrane where Armadillo is located.
Publication Types:
Research Support, Non-U.S. Gov't
PMID: 16224820 [PubMed - indexed for MEDLINE]
3: Biochem Soc Trans. 2006 Nov;34(Pt 5):687-90.
The molecular mechanisms of the mammalian exocyst complex in exocytosis.
Wang S, Hsu SC.
Department of Cell Biology and Neuroscience, Rutgers University, Nelson Biological Laboratories, 604
Allison Rd, D419, Piscataway, NJ 08854, USA.
Exocytosis is a highly ordered vesicle trafficking pathway that targets proteins to the plasma
membrane for membrane addition or secretion. Research over the years has discovered many
proteins that participate at various stages in the mammalian exocytotic pathway. At the early stage of
exocytosis, co-atomer proteins and their respective adaptors and GTPases have been shown to play a
role in the sorting and incorporation of proteins into secretory vesicles. At the final stage of exocytosis,
SNAREs (soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor) and SNAREassociated proteins are believed to mediate the fusion of secretory vesicles at the plasma membrane.
There are multiple events that may occur between the budding of secretory vesicles from the Golgi
and the fusion of these vesicles at the plasma membrane. The most obvious and best-known event is
the transport of secretory vesicles from Golgi to the vicinity of the plasma membrane via microtubules
and their associated motors. At the vicinity of the plasma membrane, however, it is not clear how
vesicles finally dock and fuse with the plasma membrane. Identification of proteins involved in these
events should provide important insights into the mechanisms of this little known stage of the
exocytotic pathway. Currently, a protein complex, known as the sec6/8 or the exocyst complex, has
been implicated to play a role at this late stage of exocytosis.
PMID: 17052175 [PubMed - in process]
4: Biochem Soc Trans. 2006 Nov;34(Pt 5):683-6.
Interactions between Rabs, tethers, SNAREs and their regulators in exocytosis.
Novick P, Medkova M, Dong G, Hutagalung A, Reinisch K, Grosshans B.
Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA.
peter.novick@yale.edu
Sec2p is the exchange factor that activates Sec4p, the Rab GTPase controlling the final stage of the
yeast exocytic pathway. Sec2p is recruited to secretory vesicles by Ypt32-GTP, a Rab controlling exit
from the Golgi. Sec15p, a subunit of the octameric exocyst tethering complex and an effector of
Sec4p, binds to Sec2p on secretory vesicles, displacing Ypt32p. Sec2p mutants defective in the region
450-508 amino acids bind to Sec15p more tightly. In these mutants, Sec2p accumulates in the cytosol
in a complex with the exocyst and is not recruited to vesicles by Ypt32p. Thus the region 450-508
amino acids negatively regulates the association of Sec2p with the exocyst, allowing it to recycle on to
new vesicles. The structures of one nearly full-length exocyst subunit and three partial subunits have
been determined and, despite very low sequence identity, all form rod-like structures built of helical
bundles stacked end to end. These rods may bind to each other along their sides to form the
assembled complex. While Sec15p binds Sec4-GTP on the vesicle, other subunits bind Rho GTPases
on the plasma membrane, thus tethering vesicles to exocytic sites. Sec4-GTP also binds Sro7p, a
yeast homologue of the Drosophila lgl (lethal giant larvae) tumour suppressor. Sro7 also binds to
Sec9p, a SNAP25 (25 kDa synaptosome-associated protein)-like t-SNARE [target-membraneassociated SNARE (soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor)],
and can form a Sec4p-Sro7p-Sec9p ternary complex. Overexpression of Sec4p, Sro7p or Sec1p
(another SNARE regulator) can bypass deletions of three different exocyst subunits. Thus promoting
SNARE function can compensate for tethering defects.
PMID: 17052174 [PubMed - in process]
5: J Cell Biol. 2006 Jul 17;174(2):207-20.
Exit from mitosis triggers Chs2p transport from the endoplasmic reticulum to mother-daughter
neck via the secretory pathway in budding yeast.
Zhang G, Kashimshetty R, Ng KE, Tan HB, Yeong FM.
Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore,
Singapore 117597.
Budding yeast chitin synthase 2 (Chs2p), which lays down the primary septum, localizes to the
mother-daughter neck in telophase. However, the mechanism underlying the timely neck localization
of Chs2p is not known. Recently, it was found that a component of the exocyst complex, Sec3p-green
fluorescent protein, arrives at the neck upon mitotic exit. It is not clear whether the neck localization of
Chs2p, which is a cargo of the exocyst complex, was similarly regulated by mitotic exit. We report that
Chs2p was restrained in the endoplasmic reticulum (ER) during metaphase. Furthermore, mitotic exit
was sufficient to cause Chs2p neck localization specifically by triggering the Sec12p-dependent
transport of Chs2p out of the ER. Chs2p was "forced" prematurely to the neck by mitotic kinase
inactivation at metaphase, with chitin deposition occurring between mother and daughter cells. The
dependence of Chs2p exit from the ER followed by its transport to the neck upon mitotic exit ensures
that septum formation occurs only after the completion of mitotic events.
Publication Types:
Research Support, Non-U.S. Gov't
PMID: 16847101 [PubMed - indexed for MEDLINE]
1: EMBO J. 2006 Apr 19;25(8):1623-34. Epub 2006 Apr 6.
Dual role of the exocyst in AMPA receptor targeting and insertion into the postsynaptic
membrane.
Gerges NZ, Backos DS, Rupasinghe CN, Spaller MR, Esteban JA.
Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109-0632,
USA.
Intracellular membrane trafficking of glutamate receptors at excitatory synapses is critical for synaptic
function. However, little is known about the specialized trafficking events occurring at the postsynaptic
membrane. We have found that two components of the exocyst complex, Sec8 and Exo70, separately
control synaptic targeting and insertion of AMPA-type glutamate receptors. Sec8 controls the
directional movement of receptors towards synapses through PDZ-dependent interactions. In contrast,
Exo70 mediates receptor insertion at the postsynaptic membrane, but it does not participate in
receptor targeting.
Thus, interference with Exo70 function accumulates AMPA receptors inside the spine, forming a
complex physically associated, but not yet fused with the postsynaptic membrane. Electron
microscopic analysis of these complexes indicates that Exo70 mediates AMPA receptor insertion
directly within the postsynaptic density, rather than at extrasynaptic membranes. Therefore, we
propose a molecular and anatomical model that dissects AMPA receptor sorting and synaptic delivery
within the spine, and uncovers new functions of the exocyst at the postsynaptic membrane.
PMID: 16601687 [PubMed - indexed for MEDLINE]