Rpb4p, a subunit of RNA polymerase II, mediates mRNA export during stress.
Changes in gene expression represent a major mechanism by which cells respond to stress. We and other investigators have previously shown that the yeast RNA polymerase II subunit Rpb4p is required for transcription under various stress conditions, but not under optimal growth conditions. Here we show that, in addition to its role in transcription, Rpb4p is also required for mRNA export, but only when cells are exposed to stress conditions. The roles of Rpb4p in transcription and in mRNA export can be uncoupled genetically by specific mutations in Rpb4p. Both functions of Rpb4p are required to maintain cell viability during stress. We propose that Rpb4p participates in the cellular responses to stress at the interface of the transcription and the export machineries.
Farago
Marganit
M
Department of Molecular Microbiology and Biotechnology, Tel-Aviv University, Ramat Aviv 69978, Israel.
Nahari
Tal
T
Hammel
Christopher
C
Cole
Charles N
CN
Choder
Mordechai
M
D000595:Amino Acid Sequence; D019084:Fluorescent Antibody Technique, Indirect; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology; D018384:Oxidative Stress; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D034443:RNA Transport / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D014158:Transcription, Genetic / Q000235:genetics
D009687:Nuclear Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D012319:RNA Polymerase II; C423309:RPB4 protein, S cerevisiae