Start Date

8-5-2013 4:00 PM

End Date

8-5-2013 5:00 PM

Subjects

Transcription factors -- Effect of temperature on, Genetic transcription, RNA polymerases, Archaebacteria, Thermophilic bacteria

Description

TFB1 and TFB2 are two Transcription Factor B (TFB) found in Pyrococcus furious (Pfu), a hyperthermophile archaeon. TFB1 is the primary TFB in Pfu, and highly conserved with eukaryotic TFIIB. TFB2 lacks some residues in B-reader region which interacts with promoter DNA and recognizes the transcription start site. Exposure to heat-shock increases the mRNA level of Pfu TFB2 in vivo; however, mRNA level of Pfu TFB1 stays the same. In Pfu, different TFBs may be used for regulating transcription. It is hypothesized that TFB2 is involved in heat-shock reaction and increases the transcription efficiency of heat-shock promoters. In our in vitro transcription assay, both TFB1 and TFB2 increase activity with increasing temperature, up to about 80C, and TFB1 has stronger activity in all temperatures and promoters. However, the rate of increase of TFB2 activity with increasing temperatures is greater than the rate for TFB1 in heat-shock promoters (PF0687 and Pf1616), compared to temperature-independent promoter (Pf1602) With Transcription Factor E (TFE) stabilizing the transcription preinitiation complex, transcription activities of TFB1 and TFB2 are enhanced, with TFB1 activity still stronger than TFB2 activity with all temperatures and promoters. TFE strongly enhances the activities of TFB2 in low temperatures, and makes the increasing rates of TFB1 and TFB2 become more similar in all promoters. These results indicate that TFB2 actives on heat-shock promoter, and TFE enhances TFB1 and TFB2's transcription activities and makes TFB2 acts more like TFB1.

Persistent Identifier

http://archives.pdx.edu/ds/psu/9476

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May 8th, 4:00 PM May 8th, 5:00 PM

Temperature Dependence of Transcription Initiation in Archaea

TFB1 and TFB2 are two Transcription Factor B (TFB) found in Pyrococcus furious (Pfu), a hyperthermophile archaeon. TFB1 is the primary TFB in Pfu, and highly conserved with eukaryotic TFIIB. TFB2 lacks some residues in B-reader region which interacts with promoter DNA and recognizes the transcription start site. Exposure to heat-shock increases the mRNA level of Pfu TFB2 in vivo; however, mRNA level of Pfu TFB1 stays the same. In Pfu, different TFBs may be used for regulating transcription. It is hypothesized that TFB2 is involved in heat-shock reaction and increases the transcription efficiency of heat-shock promoters. In our in vitro transcription assay, both TFB1 and TFB2 increase activity with increasing temperature, up to about 80C, and TFB1 has stronger activity in all temperatures and promoters. However, the rate of increase of TFB2 activity with increasing temperatures is greater than the rate for TFB1 in heat-shock promoters (PF0687 and Pf1616), compared to temperature-independent promoter (Pf1602) With Transcription Factor E (TFE) stabilizing the transcription preinitiation complex, transcription activities of TFB1 and TFB2 are enhanced, with TFB1 activity still stronger than TFB2 activity with all temperatures and promoters. TFE strongly enhances the activities of TFB2 in low temperatures, and makes the increasing rates of TFB1 and TFB2 become more similar in all promoters. These results indicate that TFB2 actives on heat-shock promoter, and TFE enhances TFB1 and TFB2's transcription activities and makes TFB2 acts more like TFB1.