2006/09/07 by Wilma A. Hofmann, Gabriela M. Vargas, Ramaswamy Ramchandran +3 · 65 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · #RNA Research and Splicing #RNA Interference and Gene Delivery #Viral Infectious Diseases and Gene Expression in Insects #RNA polymerase II #Transcription factor II F #General transcription factor #Transcription (linguistics) #Transcription factor II D #Transcription factor II B #RNA polymerase II holoenzyme #Molecular biology #Polymerase #Biology #Cell biology #Chemistry #RNA-dependent RNA polymerase #Biochemistry #DNA #Promoter #Gene expression #Gene
paper · doi:10.1002/jcb.21035
published in Journal of Cellular Biochemistry 99(4), 1001-1009 (Wiley)
openalex publication_date 2006/09/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/01/13
The nuclear isoform of myosin, Nuclear Myosin I (NMI) is involved in transcription by RNA polymerase I. Previous experiments showing that antibodies to NMI inhibit transcription by RNA polymerase II using HeLa cell nuclear extract (NE) suggested that NMI might be a general transcription factor for RNA polymerases. In this study we used a minimal in vitro transcription system to investigate the involvement of NMI in transcription by RNA polymerase II in detail. We demonstrate that NMI co-purifies with RNA polymerase II and that NMI is necessary for basal transcription by RNA polymerase II because antibodies to NMI inhibit transcription while adding NMI stimulates transcription. Further investigation revealed that NMI is specifically involved in transcription initiation. Finally, by employing an abortive transcription initiation assay, we demonstrate that NMI is crucial for the formation of the first phosphodiester bond during transcription initiation.