SRPK2
Description
The SRPK2 (SRSF protein kinase 2) is a protein-coding gene located on chromosome 7.
Serine/threonine-protein kinase SRPK2 is an enzyme that in humans is encoded by the SRPK2 gene.
== Interactions == SRPK2 has been shown to interact with:
ASF/SF2 and U2AF2.
SRPK2 is a serine/arginine-rich protein-specific kinase that phosphorylates its substrates at serine residues within arginine/serine-rich regions, known as RS domains. It plays a role in the phosphorylation of SR splicing factors and the regulation of splicing. SRPK2 promotes neuronal apoptosis by upregulating cyclin-D1 (CCND1) expression through the phosphorylation of SRSF2, which suppresses p53/TP53 phosphorylation and relieves its repressive effect on CCND1 expression. SRPK2 phosphorylates ACIN1, relocating it from nuclear speckles to the nucleoplasm and leading to cyclin A1 but not cyclin A2 upregulation. SRPK2 is crucial for spliceosomal B complex formation via DDX23/PRP28 phosphorylation. By phosphorylating DDX23, SRPK2 likely suppresses incorrect R-loops formed during transcription. R-loops consist of a DNA:RNA hybrid and the associated non-template single-stranded DNA. SRPK2 can mediate hepatitis B virus (HBV) core protein phosphorylation and negatively regulates HBV replication by reducing pregenomic RNA (pgRNA) packaging efficiency without affecting viral core particle formation. SRPK2 associates with U4/U6-U5 tri-small nuclear ribonucleoproteins (U4/U6-U5 tri-snRNPs). It interacts with PKB/AKT1 in a phosphorylation-dependent manner, and its phosphorylated form interacts with YWHAB and YWHAE. The interaction with YWHAB suppresses its caspase cleavage and inhibits the release of its pro-apoptotic N-terminal fragment. SRPK2 interacts with SFN and ACIN1. It also interacts with POLR2A/RNA polymerase II during the co-transcriptional formation of inappropriate R-loops.
SRPK2 is also known as SFRSK2.
