Human La is found at RNA polymerase III-transcribed genes in vivo.
The human La autoantigen can bind to nascent RNA transcripts and has also been postulated to act as an RNA polymerase III (pol III) transcription initiation and termination factor. Here, we show by chromatin immunoprecipitation (ChIP) that La is associated with pol III-transcribed genes in vivo. In contrast, the Ro autoantigen, which can also bind pol III transcripts, is not found at these genes. The putative pol III transcription factors NF1 and TFIIA are also not detected at class III genes. Binding of La remains when transcription is repressed at mitosis and does not correlate with the presence of polymerase at the gene. However, gene occupancy depends on the phosphorylation status of La, with the less prevalent, unphosphorylated form being found selectively on pol III templates.
Fairley
Jennifer A
JA
Institute of Biomedical and Life Sciences, Division of Biochemistry and Molecular Biology, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
Kantidakis
Theodoros
T
Kenneth
Niall S
NS
Intine
Robert V
RV
Maraia
Richard J
RJ
White
Robert J
RJ
D001324:Autoantigens / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D025542:Neurofibromin 1 / Q000378:metabolism; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D012320:RNA Polymerase III / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D013698:Templates, Genetic; D035561:Transcription Factor TFIIA / Q000378:metabolism; D014158:Transcription, Genetic; D000097585:SS-B Antigen; D000099207:SS-A Antigen
D001324:Autoantigens; D025542:Neurofibromin 1; D012320:RNA Polymerase III; D012261:Ribonucleoproteins; D035561:Transcription Factor TFIIA; D000097585:SS-B Antigen; D000099207:SS-A Antigen