Transcription factor IIA of wheat and human function similarly with plant and animal viral promoters

Abstract

Eucaryotic transcription initiation by RNA polymerase II involves protein:DNA interactions during the formation of a transcription complex. In addition to RNA polymerase II there are at least five other general transcription factors necessary for initiation with the adenovirus major late promoter. One of these, TFIIA, is involved in the earliest events during transcription complex assembly. We have purified TFIIA from wheat germ and characterized it in an in vitro transcription system. Wheat TFIIA is a single polypeptide of Mr approximately 35 kd which functionally replaces human (HeLa) TFIIA to form a wheat/HeLa transcription system. [This polypeptide can be eluted from a SDS-polyacrylamide gel, refolded to a native conformation, and will function as wheat TFIIA in the heterologous system.] The heterologous system requires a lower optimal incubation temperature than the HeLa system. Biochemical characterization, using the adenovirus major late promoter, indicates that transcription reaction parameters for both wheat and HeLa TFIIA are similar but the kinetics of transcription for both TFIIAs are somewhat dissimilar. A plant viral promoter, the cauliflower mosaic virus 35S promoter, accurately and efficiently directs in vitro transcription in both the wheat/HeLa and HeLa systems with identical transcription kinetics. We conclude that TFIIA function has been conserved during evolution.

Factors involved in specific transcription by mammalian RNA polymerase II: purification and analysis of transcription factor IIA and identification of transcription factor IIJ.

“…Since no other polypeptide that contained the transcriptionstimulatory activity could be renatured and the polypeptides required to reconstitute the stimulatory effect on TBP DNA binding activity coeluted with the transcription-stimulatory activity (Fig. 1A) 13-kDa polypeptides (39) and from wheat and HeLa cells as a 35-kDa polypeptide (6,46). TFIIA has also been identified in S. cerevisiae, but its polypeptide composition is still unknown (4,18).…”

Transcriptional and post-transcriptional regulation of gene expression in plants

“…TFIIA appears to be very similar to its animal counterpart [11 ]. TFIID, which has some homology to bacterial sigma factor, binds to the TATA box and thus may be a key determinant of the transcription initiation site.…”

The New Genetics and Natural versus Artificial Genetic Modification

“…The CaMV 35S promoter supported high levels of reporter gene expression in mature Xenopus oocytes [114] and gave very efficient transcription in extracts of nuclei from HeLa cells (a human cell line) [115].…”