High impact information on RpII33

• The previously described B factor (an RNA polymerase II transcription factor that binds to the TATA box), isolated from nonshocked cells, is significantly reduced in both binding and transcriptional activity in heat-shocked cells [1].
• This factor is required for active transcription of an hsp 70 gene in addition to RNA polymerase II and another general transcription factor, the A factor [1].
• That this change occurred in the absence of endogenous RNA polymerase II activity suggests that these changes may reflect the earliest event in gene activation [2].
• We show that Pcf11 is directly involved in termination in Drosophila. dPcf11 is concentrated at the 3' end of the hsp70 gene in cells, and depletion of dPcf11 with RNAi causes Pol II to readthrough the normal region of termination. dPcf11 also localizes to most transcribed loci on polytene chromosomes [3].
• Unlike the TAFs and Pol II, the interaction between Mediator and HSF on chromosomal loci is direct and mechanistically separable from the preinitiation complex assembly step [4].

Biological context of RpII33

• Phosphorylation state of the RNA polymerase II C-terminal domain (CTD) in heat-shocked cells. Possible involvement of the stress-activated mitogen-activated protein (MAP) kinases [5].
• Further, the data indicate that T residues at positions 2 and 4 of the TATA box appear to be important determinants of RNAP III selectivity in this system, whereas A residues at these positions favor RNAP II transcription [6].
• Here, we show that upon heat shock the Pol II-free form of Mediator is rapidly recruited to HSF binding sites [4].
• Transcriptional enhancers for genes transcribed by RNA polymerase II may be localized upstream or downstream of the stimulated promoter in their normal chromosomal context [7].
• Rtt109 Is Required for Proper H3K56 Acetylation: A CHROMATIN MARK ASSOCIATED WITH THE ELONGATING RNA POLYMERASE II [8].

Anatomical context of RpII33

• Reduction of BRM function dramatically reduces the association of RNA polymerase II with salivary gland chromosomes [9].
• Sheep antibodies to Drosophila RNA polymerase were found to react with most polypeptides of the insect RNA polymerases but only with the high-molecular weight subunits of calf thymus RNA polymerase II [10].

Associations of RpII33 with chemical compounds

• Flavopiridol inactivates P-TEFb and blocks most RNA polymerase II transcription in vivo [11].
• We found that the flavonoid potently inhibited transcription by RNA polymerase II in vitro by blocking the transition into productive elongation, a step controlled by P-TEFb [12].

Other interactions of RpII33

• The P1 region directs divergent transcription of the pol gamma-beta gene and the adjacent rpII33 gene [13].

Analytical, diagnostic and therapeutic context of RpII33

• Antisera were generated against bacterially expressed RPII15 and were used for immunoblotting experiments with RNA polymerase II of Drosophila melanogaster [14].
• The chromatin immunoprecipitation assays revealed that HDI treatments induced the hyperacetylation of histone H3 at the promoter and the transcribing regions of hsp70 gene, increased the accessibility of heat-shock factor to target heat-shock element, and promoted the RNA polymerase II-mediated transcription [15].
• Antibodies reactive against mammalian RNA polymerase II were isolated by affinity chromatography [16].

References