RNA helicase A acts as a bridging factor linking nuclear beta-actin with RNA polymerase II.
Actin, the major component of the cytoplasmic skeleton, has been shown to exist in the nucleus. Nuclear actin functions in several steps of the transcription process, including chromatin remodelling and transcription initiation and elongation. However, as a part of PICs (pre-initiation complexes), the role of actin remains to be elucidated. In the present study, we identified RHA (RNA helicase A) as an actin-interacting protein in PICs. Using immunoprecipitation and immunofluorescence techniques, we have shown that RHA associates with beta-actin in the nucleus. A GST (glutathione transferase) pulldown assay using different deletion mutants revealed that the RGG (Arg-Gly-Gly) region of RHA was responsible for the interaction with beta-actin, and this dominant-negative mutant reduced the recruitment of Pol II (RNA polymerase II) into PICs. Moreover, overexpression or depletion of RHA could influence the interaction of Pol II with beta-actin and beta-actin-involved gene transcription regulation. These results suggest that RHA acts as a bridging factor linking nuclear beta-actin with Pol II.
Tang
Wen
W
Institute of Genetics and Cytology, Northeast Normal University, Changchun, Jilin, People's Republic of China.
You
Wanhui
W
Shi
Feng
F
Qi
Tianyang
T
Wang
Ling
L
Djouder
Zina
Z
Liu
Wenguang
W
Zeng
Xianlu
X
D000199:Actins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D011485:Protein Binding; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D000199:Actins; D008156:Luciferases; D012319:RNA Polymerase II; D020365:RNA Helicases