FUNCTION: SwissProt: P48730 # Casein kinases are operationally defined by their preferential utilization of acidic proteins such as caseins as substrates. It can phosphorylate a large number of proteins. Participates in Wnt signaling. Central component of the circadian clock. May act as a negative regulator of circadian rhythmicity by phosphorylating PER1 and PER2. Retains PER1 in the cytoplasm.
SIZE: 415 amino acids; 47330 Da
SUBUNIT: Monomer. Component of the circadian core oscillator, which includes the CRY proteins, CLOCK, or NPAS2, BMAL1 or BMAL2, CSNK1D and/or CSNK1E, TIMELESS and the PER proteins. Interacts directly with PER1 and PER2 which may lead to their degradation.
SUBCELLULAR LOCATION: Cytoplasm.
TISSUE SPECIFICITY: Expressed in all tissues examined, including brain, heart, lung, liver, pancreas, kidney, placenta and skeletal muscle. In blood, highly expressed in hemopioetic cells and mature granulocytes. Also found in monocytes and lymphocytes.
PTM: Autophosphorylated on serine and threonine residues (By similarity).
DISEASE: "SwissProt: P48730 # Defects in CSNK1D are a cause of familial advanced sleep- phase syndrome (FASPS) [MIM:604348]. FASPS is characterized by very early sleep onset and offset. Individuals are 'morning larks' with a 4 hours advance of the sleep, temperature and melatonin rhythms."
SIMILARITY: SwissProt: P48730 ## Belongs to the protein kinase superfamily. CK1 Ser/Thr protein kinase family. Casein kinase I subfamily. & Contains 1 protein kinase domain.