Integrator Complex Subunit 9 (INTS9)

INTS9 encodes a subunit of the Integrator complex. This protein complex binds the C-terminal domain of RNA polymerase II and likely plays a role in small nuclear RNA processing. The encoded protein has similarities to the subunits of the cleavage and polyadenylation specificity factor complex. Alternatively spliced transcript variants have been described.

The deduced 658-amino acid protein contains mutations within the catalytic histidine motif, suggesting that it is inactive. Fluorescence- and epitope-tagged INTS9 was expressed exclusively in the nucleus of transfected HeLa cells.full-length RC74 interacted with C-terminal fragments of RC68 (CPSF3L) and full-length importin-alpha (KPNA2).