Biochemistry Seminar: Michael Hampsey, Rutgers - UMDNJ
Wed, Apr 23
12:00 PM — 1:00 PM
MarshakCity College of New York160 Convent Ave
Marshak, MR 1027
Michael Hampsey, Prof., Rutgers, will give a talk on "Gene Loops Facilitate mRNA Export"Michael Hampsey, Prof., Dept of Biochemistry & Mol Biology, Rutgers-UMDNJ, "Gene Loops Facilitate mRNA Export"
Gene loops juxtapose the promoter and terminator regions of genes in yeast and mammalian cells. Gene loops are formed on RNA Pol II-transcribed genes and are dependent upon the transcription initiation factor TFIIB and components of the pre-mRNA 3’-end processing machineries. We are engaged in a systematic analysis of the genetic and physical requirements for looping. Looping is RNA-dependent, requires specific components of the TREX-1 and TREX-2 complexes that couple transcription with mRNA export, and occurs prior to translocation of loops to the nuclear pore complex. Earlier work from Hannah Klein’s laboratory identified defects in TFIIB (sua7/soh4) as suppressors of the growth defect associated with deletion of the Hpr1 component of the TREX-1 complex (Fan, HY, Cheng, KK and Klein, HL (1996) Genetics, 142:749-59). We find that the hpr1Δ mutant is defective for both loop formation and mRNA accumulation in the cytoplasm. Moreover, the sua7/soh4 suppressors restore looping as well as mRNA export. We propose a model whereby gene loops interact with the nuclear pore complex to facilitate export of nascent mRNA to the cytoplasm.