a transcription elongation factor. Component of the DRB sensitivity-inducing factor complex (DSIF complex), which regulates mRNA processing and transcription elongation by RNA polymerase II. DSIF positively regulates mRNA capping by stimulating the mRNA guanylyltransferase activity of RNGTT. DSIF also acts cooperatively with the negative elongation factor complex (NELF complex) to enhance transcriptional pausing at sites proximal to the promoter. Two alternatively spliced human isoforms have been described. Note: This description may include information from UniProtKB.
Protein type: RNA-binding; Transcription, coactivator/corepressor
Molecular Function: enzyme binding; protein binding; protein heterodimerization activity
Biological Process: mRNA capping; negative regulation of RNA elongation; negative regulation of transcription from RNA polymerase II promoter; positive regulation of macroautophagy; positive regulation of RNA elongation; positive regulation of transcription from RNA polymerase II promoter; positive regulation of viral transcription; response to organic substance; RNA elongation; RNA elongation from RNA polymerase II promoter; transcription from RNA polymerase II promoter