PSKH1 (protein serine kinase H1) is a 424 amino acid protein that localizes to a variety of places within the cell, including the Golgi apparatus, nuclear speckles, centrosomes and the membrane of the endoplasmic reticulum. Expressed ubiquitously, PSKH1 belongs to the Ser/Thr protein kinase family and functions as a splicing factor compartment-associated serine kinase that is thought to play a role in mRNA processing and SR (serine/arginine) protein trafficking events. PSKH1 contains one protein kinase domain and exists as a homodimer that is subject to autophosphorylation on specific serine residues.