Salt Inducible Kinase 2 (SIK2)

The SIK2 transcript contains 2 repetitive elements in the 3-prime UTR. RT-PCR ELISA detected moderate to high expression in all tissues examined. Highest expression was in kidney, followed in order by brain, ovary, heart, lung, skeletal muscle, pancreas, testis, and spleen. Sik2 contains an N-terminal serine/threonine protein kinase domain, a central domain with a ubiquitin-associate motif, and a C-terminal protein kinase A phosphorylation site. Northern blot analysis of several mouse tissues detected transcripts of 4.0 and 6.0 kb. Highest expression was in white adipose and brown adipose tissues. Testis showed intermediate Sik2 expression, and much lower expression was found in all other tissues examined. Fluorescence-labeled Sik2 was expressed mostly in the cytoplasm of transfected mouse preadipocytes.