Developing a collaboration to enable chemical dissection of second messenger
signaling networks
Dr. Dorothea Fiedler, Department of Chemistry, Princeton University
Dr. Stuart J. Conway, Department of Chemistry, University of Oxford
Background
DF and SJC met at the 2010 Spring American Chemical Society meeting following DF’s lecture.
They have a mutual interest in the application of chemical tools to investigate inositol‐based
cellular signaling networks. SJC’s expertise in the synthesis of inositol‐based chemical probes
and DF’s expertise in molecular biology/genetics is highly complementary and hence both SJC
and DF are keen to develop a successful collaboration.
Aims
• To hold two small, focused, symposia on the chemistry‐biology interface of inositol signaling.
• To hold two planning meetings to develop proposals for collaborative research funding, from
USA, UK and international sources.
Significance of research
Since the discovery, in 1983, that the inositol‐based signaling molecule, InsP3, is a
calcium‐releasing second messenger, phosphorylated inositols have emerged as a major class
of intracellular messenger. In the intervening period, endeavors in both synthetic chemistry and
molecular/structural biology have advanced our understanding of the fundamental roles played
by these molecules. It is now clear that inositol–polyphosphates are important regulators for
many cellular processes, including cell survival, cell proliferation, muscle contraction and the
molecular basis of learning and memory. Despite this progress, many of their signaling
functions have remained elusive, because these metabolites are difficult to study with standard
cell biology techniques. Their chemical tractability, however, provides the unique opportunity
to investigate their functions with chemical tools. We therefore posit that a combined chemical
synthesis and molecular biology approach is essential for sustained progress in our
understanding of inositol phosphate signaling.
Inositol contains six positions at which chemical modification, most commonly phosphorylation,
can occur. Molecules containing many of the possible combinations of substitution have been
chemically synthesized and their biological actions assessed. These modifications have almost
exclusively involved substitution of a single phosphate moiety at the given position. However,
among the many derivatives of the inositol phosphate messengers is a subgroup that possesses
high‐energy diphosphate (pyrophosphate) groups. This intriguing class of inositol
pyrophosphates has been linked to several cellular functions, including telomere maintenance,
and protein phosphorylation. Moreover, it has been demonstrated that the diphosphoinositol
phosphates are intimately involved in insulin secretion, glucose uptake, and the metabolic state
of cancer cells. However, by comparison, the study of the inositol pyrophosphate is an
emerging area with little known about these new chemical messengers or their cellular targets.
DF and SJC plan to combine their synthetic and molecular biology skills to systematically analyze
the role of these molecules and determine their cellular targets. Many molecular probes for
other inositol‐based signaling molecules have been developed, but, although a synthesis of an
inositol pyrophosphate (InsP7) has recently been reported, no such tools have yet been
developed to probe the role of the inositol pyrophosphates. SJC’s research group has the
expertise to synthesize molecular probes that include membrane permeant, light‐activated,
hydrolysis resistant and photo‐cross linking derivatives of the various inositol pyrophosphates
in addition to affinity matrices to determine the molecular targets of these compounds.
However, the syntheses of these molecules are technically challenging and time‐consuming.
Therefore, external funds will need to be obtained before significant progress can be made in
this area. DF’s lab would greatly benefit from SJC’s expertise in synthesizing InsP7 analogues. In
DF’s lab, these analogues are to be evaluated in the relevant cell models, in combination with
different genetic perturbations. This will allow us to assign discrete signaling functions to these
second messengers.
Herein we request funding to facilitate the planning required to make several applications for
joint funding to address the exciting challenges outlined above.
Outline of planning activities
Year 1: In year one we will organize two focused symposia on the Chemical Biology of Inositol
Signaling. The purpose of these symposia will be to educate the students and PDRAs in the
Oxford‐Princeton team in recent developments in the biology and chemistry of this area. The
symposia will also provide excellent networking opportunities for DF and SJC. The first
symposium will be held in Oxford in the 2011 Easter vacation. The format will be based loosely
on that of a Gordon conference, with no predetermined agenda and maximum time for
discussion. In addition to the core Oxford‐Princeton team, we will invite several UK‐based
experts in the chemistry and/or biology of inositol signaling. These experts will include some or
all of the following: Prof. Antony Galione (Pharmacology, Oxford); Prof. Sir Michael Berridge
(Babraham Institute, Cambridge); Dr. Martin Bootman (Babraham Institute, Cambridge); Prof.
Barry Potter (Pharmacology, Bath) and Prof. Adolfo Saiardi (Cell and Developmental Biology,
UCL).
The second symposium will be held at Princeton in the 2011 Summer vacation and will have the
same format as above. In this instance, we will invite several USA‐based experts in the
chemistry and/or biology of inositol signaling. These experts will include some or all of the
following: Prof. Scott Miller (Chemistry, Yale), Prof. Glenn Prestwich (Medicinal Chemistry, Salt
Lake City), Dr. Stephen Shears (NIH, RTP) and Prof. Solomon Snyder (Johns Hopkins University,
Baltimore).
Year 2: In year two we will hold two planning meetings, one in Oxford and one in Princeton, to
develop proposals for research funding from external agencies.
Summary
In summary, the funding requested will catalyze a new collaboration between two early career
stage researchers at Oxford and Princeton. Joint funding applications, joint projects and novel
ideas will result from this funding. Without the requested funding, it is likely that this
collaboration will take much longer to initiate and reach a point where credible applications for
external funding can be made.