Identification of tyrosine 972 as a novel site of Jak2 tyrosine kinase phosphorylation and its role in Jak2 activation.

ABSTRACT: Jak2 is a 130 kDa tyrosine kinase that is important in a number of cellular signaling pathways. Its function is intrinsically regulated by the phosphorylation of a handful of its 49 tyrosines. Here, we report that tyrosine 972 (Y972) is a novel site of Jak2 phosphorylation and, hence, autoregulation. Specifically, we found that Y972 is phosphorylated and confirmed that this residue resides on the surface of the protein. Using expression plasmids that expressed either wild-type Jak2 or a full-length Jak2 cDNA containing a single Y972F substitution mutation, we investigated the consequences of losing Y972 phosphorylation on Jak2 function. We determined that the loss of Y972 phosphorylation significantly reduced the levels of both Jak2 total tyrosine phosphorylation and phosphorylation of Y10

SUBMITTER: McDoom I 

PROVIDER: S-EPMC3636534 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature