PSK
The PSK group is a small CAMK-family branch containing the serine/threonine protein kinases H1 and H2, PSKH1 and PSKH2. PSKH1 was originally isolated by homology cloning and encodes a catalytic domain most similar to calcium/calmodulin-dependent kinases, although classic calmodulin regulation remains incompletely established. PSKH1 localizes to the Golgi and cytoplasm, undergoes autophosphorylation, and has been implicated in cell cycle progression and messenger RNA splicing through association with spliceosomal proteins. PSKH2 is a close paralog with largely unexplored function. The group illustrates CAMK-family members that adopted housekeeping rather than calcium-triggered roles, and both kinases remain comparatively understudied.
