Disease relevance of SPBC36.07

• The aim of this work was to identify proteins from Adenovirus 2-infected HeLa cell extracts that interact with the carboxyl-terminal domain of the largest subunit of RNA polymerase II [1].

High impact information on SPBC36.07

• Additional outstanding questions include the patterns of promoter-specificity of the various Mediator subunits, the possible cell-type-specificity of Mediator subunit composition, and the full structures of both free Mediator and RNA polymerase II holoenzyme [2].
• RNA polymerase II initiation factor interactions and transcription start site selection [3].
• Recently, Rpb1 and Rpb2 subunits of RNA polymerase II (RNA Pol II) were shown to mediate RNA interference (RNAi)-directed chromatin modification but did not affect pre-siRNA levels [4].
• Functionally, TFIIH has been implicated in transcription by RNA polymerase II (RNAPII) and in nucleotide excision repair [5].
• A role for chromatin remodeling in transcriptional termination by RNA polymerase II [6].

Biological context of SPBC36.07

• Capping of nascent pre-mRNAs is thought to be a prerequisite for productive elongation and associated serine 2 phosphorylation of the C-terminal domain (CTD) of RNA polymerase II (PolII) [7].
• Whereas CAKs in animals and fission yeast are involved in regulation of the cell cycle and basal transcription by phosphorylating the carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II, Cak1At did not phosphorylate the CTD [8].
• A novel domain in Set2 mediates RNA polymerase II interaction and couples histone H3 K36 methylation with transcript elongation [9].
• Functional organization of two large subunits of the fission yeast Schizosaccharomyces pombe RNA polymerase II. Location of the catalytic sites [10].
• SpCdk9/Pch1 also phosphorylates the CTD heptaptide repeat array of the largest subunit of S. pombe RNA polymerase II (consensus sequence YSPTSPS) and does so exclusively on serine [11].

Anatomical context of SPBC36.07

• The distribution of RNA polymerase II and morphological details that could be observed in the extra-nucleolar region of cryofixed cells provided cytological evidence of a peripheral region extending along the nuclear envelope that could correspond to heterochromatin in higher eukaryotes [12].

Associations of SPBC36.07 with chemical compounds

• Factor g can stably associate with RNA polymerase II, as shown by cosedimentation in a glycerol gradient [13].
• Set2 methylation of histone H3 at lysine 36 (K36) has recently been shown to be associated with RNA polymerase II (Pol II) elongation in Saccharomyces cerevisiae [14].

Other interactions of SPBC36.07

• To gain an insight into the roles of subunit 3, the eukaryotic homologue of alpha, temperature-sensitive mutants of the fission yeast, Schizosaccharomyces pombe, have been isolated after transformation of the mutagenized rpb3 gene encoding mutant subunit 3 of RNA polymerase II [15].
• Importantly, Mediator containing the spSrb8/spTrap240/spSrb10/spSrb11 subunits is isolated only in free form, devoid of RNA polymerase II [16].
• Cyclin-dependent kinase 9 (Cdk9) of fission yeast is an essential ortholog of metazoan positive transcription elongation factor b (P-TEFb), which is proposed to coordinate capping and elongation of RNA polymerase II (Pol II) transcripts [17].
• A notable exception is a 19-bp block, centered 36 nucleotides upstream from the transcriptional start site, in which the two loci match in 15 positions; this motif may represent an RNA polymerase II upstream regulatory element, because related sequences are found preceding fission yeast U1, U2, U4, and U5 snRNA genes [18].
• In this report, characterization of XPB mutants indicates that its helicase activity is not used for RNA polymerase II promoter opening, which is instead driven by its ATPase activity [19].

Analytical, diagnostic and therapeutic context of SPBC36.07

• Cloning and sequence determination of the Schizosaccharomyces pombe rpb1 gene encoding the largest subunit of RNA polymerase II [20].
• First, a mammalian RNA polymerase II complex was isolated from Adenovirus 2-infected HeLa cell extracts by affinity chromatography against the carboxyl-terminal domain of the largest subunit of RNA polymerase II, followed by chromatography on a Mono S fast protein liquid chromatographic column [1].
• The fission yeast Rpb4 subunit of RNA polymerase II plays a specialized role in cell separation [21].

References