11-13 May 2012 Helsingør - Denmark www.networkbio.org

abStract For SPeakerS
MAREIKE WEIMANN*, JONAThAN WOODSMITh*, ARNDT GROSSMANN, zIYA …zKAN, PETRA BIRTh,
DAVID MEIERhOfER, SASChA SAUER, ULRICh STELzL OTTO-WARBURG LABORATORY, MAx-PLANCK
INSTITUTE fOR MOLECULAR GENETICS (MPIMG)
A Y2H-seq approach to define the protein methyltransferase interactome
Protein methylation, in particular on arginine and lysine residues, is an important, widespread postranslational
modification. The large number of human methyltransferases, potential demethylases and Merecognition
domain containing proteins, which are not only expressed in a large variety of tissues but also at
different subcellular localizations, indicate roles in many cellular processes other than epigenetic regulation.
However, the transient nature of substrate enzyme recognition, the lack of affinity reagents and appropriate
tools to detect methyltransferase substrate pairs largely hampered progress in defining the global role of
non-histone protein methylation.
Here we present a novel proteome wide Y2H protein interaction screening approach involving a second
generation sequencing readout. The method has significantly improved sensitivity in comparison to our state
of the art Y2H matrix screening protocol. Importantly, 2nd generation sequencing provides a quantitative
readout that correlates very well with the retest success rate indicative of the quality of the PPI information.
Y2H-seq will thus accelerate large scale interactome mapping efforts.
We applied the Y2H-seq method to comprehensively screen proteins involved in methylation and demethylation,
i.e. protein methyl transferases (PMTs) and JMJ-domain containing putative demethylases
(PDeMs) such as LSM1, for interacting proteins. We found more than 500 interactions involving 22 PMTs
and PDeMs and 324 potential methylation substrates. Exemplarily, 7 candidate proteins are characterized
with respect to novel R and K methylation sites using a mass spectrometry approach. The final network is
comprehensively annotated, validated in co-IP experiments and will serve as a major informational resource
to define cellular roles of non-histone protein methylation.
abStract For SPeakerS
A.J. MARIAN WALhOUT
UNIVERSITY Of MASSAChUSETTS MEDICAL SChOOL
WORCESTER, MA
A.J. Marian Walhout obtained her BS and PhD degrees in Biochemistry/Medicine
from Utrecht University in the Netherlands. After a post-doc at Harvard
Medical School, she became a Faculty member at the University of Massachusetts
Medical School, Worcester, USA in 2003. She is currently a Professor
in Molecular Medicine and a Co-Director of the Program in Systems Biology.
Gene regulatory networks
Transcriptional regulation of gene expression is pivotal to all biological processes.
Each of our ~20,000 genes must be expressed at the right place, time
and level, and under the right conditions. As a consequence, improper gene expression is associated with
a myriad of human diseases, including congenital disorders, cancer and obesity. The basic mechanisms
of RNA polymerase II transcription have been studied in great detail for decades. However, little is known
about the gene regulatory networks (GRNs) that are composed of physical and regulatory interactions
between transcription factors and their target genes, and that orchestrate spatiotemporal gene expression
during development or upon physiological stresses and pathological insults. Our long-term goal is to comprehensively
characterize the structure, function and evolution of complex metazoan GRNs. As a model we
use the nematode C. elegans, which is amenable to a variety of genetic and genomic approaches. We have
developed a variety of gene-centered methods for the elucidation of GRNs. Progress will be discussed.
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