S. cerevisiae RPB4

Full Name

DNA-directed RNA polymerase II subunit RPB4

Function

DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Component of RNA polymerase II which synthesizes mRNA precursors and many functional non-coding RNAs. Pol II is the central component of the basal RNA polymerase II transcription machinery. It is composed of mobile elements that move relative to each other. RPB4 is part of a subcomplex with RPB7 that binds to a pocket formed by RPB1, RPB2 and RPB6 at the base of the clamp element. The RBP4-RPB7 subcomplex seems to lock the clamp via RPB7 in the closed conformation thus preventing double-stranded DNA to enter the active site cleft. The RPB4-RPB7 subcomplex binds single-stranded DNA and RNA. The RPB4-RPB7 subcomplex is necessary for promoter-directed transcription initiation but is not required for recruitment of Pol II to active preinitiation complexes and seems to be dispensable for transcription elongation and termination. The RPB4-RPB7 subcomplex recruits FCP1 to Pol II. Involved in DNA repair of damage in the transcribed strand. RPB4 is dispensable under optimal growth conditions, but becomes essential during heat or cold shock and under nutrient depletion. Suppresses the RBP9-mediated transcription-coupled repair (TCR) subpathway of nucleotide excision repair (NER) but facilitates the RAD26-mediated TCR subpathway. Under stress conditions only, involved in mRNA export to the cytoplasm. Involved in mRNA decay. Promotes or enhances the deadenylation process of specific mRNAs and may recruit PAT1 and the LSM1-7 complex to these mRNAs, thus stimulating their decapping and further decay.

Biological Process

Biological Process mRNA export from nucleus in response to heat stressManual Assertion Based On ExperimentIMP:SGD
Biological Process nuclear-transcribed mRNA catabolic process, deadenylation-dependent decayManual Assertion Based On ExperimentIMP:SGD
Biological Process positive regulation of translational initiationManual Assertion Based On ExperimentIMP:SGD
Biological Process recruitment of 3'-end processing factors to RNA polymerase II holoenzyme complexManual Assertion Based On ExperimentIMP:SGD
Biological Process RNA-templated transcriptionIEA:GOC
Biological Process transcription by RNA polymerase IIManual Assertion Based On ExperimentIMP:SGD
Biological Process transcription elongation by RNA polymerase II promoterManual Assertion Based On ExperimentIDA:ComplexPortal
Biological Process transcription initiation at RNA polymerase II promoterManual Assertion Based On ExperimentIDA:SGD

Cellular Location

Nucleus
Cytoplasm
Cytoplasm, P-body
Seems to shuttle between nucleus and cytoplasm in a complex with RPB7.