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SUMMARY:Evolution and Dynamics of Transcriptional Regulatory Networks - Dr
  Sarah Teichmann\, (MRC Laboratory of Molecular Biology)
DTSTART:20060623T134000Z
DTEND:20060623T142500Z
UID:TALK5088@talks.cam.ac.uk
CONTACT:Duncan Simpson
DESCRIPTION:Evolution and dynamics of transcription factor repertoires \n\
 nSarah A. Teichmann\, MRC Laboratory of Molecular Biology\,\nCambridge\, U
 K.\n\nRegulation of gene expression influences almost all biological proce
 sses in an organism\, and sequence-specific DNA-binding transcription fact
 ors are critical to this control. These transcription factors are involved
  in complex circuits of regulation between transcription factors and targe
 t genes (Babu et al.\, 2004). Transcription factors that bind specific DNA
 \nsequences are arguably the core information-carrying molecules in regula
 tory networks\, and are therefore of particular interest in understanding 
 the evolution of organismal complexity.\n\nHowever\, for most genomes\, th
 e repertoire of transcription factors is only partially known. To fill thi
 s void\, we have developed a novel transcription \nfactor identification m
 ethod\, providing genome-wide transcription factor predictions for organis
 ms from across the tree of life\, available at www.transcriptionfactor.org
  (Kummerfeld & Teichmann\, 2006).\n\nBy integrating annotated transcriptio
 n factors with expression data\, we have started to gain insight into the 
 dynamics of transcription factor expression under different cellular condi
 tions in a unicellular organism (Luscombe et al\,. 2004) and in different 
 developmental\nstages and tissues in a multi-cellular organism. Both analy
 ses reveal the importance of combinatorial action of transcription factors
  to determine the state of a cell\, and the role of ubiquitous transcripti
 on factor hubs.\n\nWe have investigated the evolution of transcription fac
 tors in both prokaryotes and eukaryotes. A general trend emerges across al
 l different groups of organisms\, showing that transcription factors\, as 
 well as other classes of regulatory molecules evolve more quickly\nthan ge
 nes in other functional categories\, such as enzymes for instance. This su
 ggests that transcription factors are 'evolvable' in the sense that duplic
 ations and losses of transcription factors are tolerated more\neasily than
  for core functional classes. The changes in transcription factor repertoi
 res are likely to play a large part in evolution of development and comple
 xity.\n\n\n\nReferences\n\nKummerfeld & Teichmann (2006) DBD: Kummerfeld\,
  S.K. & Teichmann\, S.A. (2006) \nDBD: a transcription factor prediction d
 atabase. Nucleic Acids Res.\, 34\, D74-81. \n\nBabu\, M.M.\, Luscombe\, N.
 M.\, Aravind\, L.\, Gerstein\, M. & Teichmann\, S.A. (2004) \nStructure an
 d evolution of transcriptional regulatory networks. Curr. Op. Struc. \nBio
 l.\, 14\, 283-291\n\nLuscombe\, N.M.\, Babu\, M.M.\, Yu\, H.\, Snyder\, M.
 \, Teichmann\, S.A.\, Gerstein\, M. (2004) Genomic analysis of regulatory\
 nnetwork dynamics reveals large topological change. Nature\, 431\, 308-312
 .\n
LOCATION:Emmanuel College Cambridge
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