Molecular cloning of a chicken JAK homolog from activated T cells.
A cDNA encoding a JAK-related protein was isolated from a chicken Tcell library by screening with a PCR-generated probe that corresponds to a conserved region in the kinase domain. Sequence analysis reveals an ORF of 3318nt, encoding a protein with a calculated molecular weight of 123000. Chicken JAK (cJAK) contains a double catalytic domain that is characteristic of the JAK family of tyrosine kinases. Compared with mammalian JAKs, the kinase domain shows 70% sequence identity with the corresponding region of the mammalian JAKs. Overall, cJAK shows approximately 59% amino acid identity with mammalian JAK3s, and 52% amino acid identity with mammalian JAK2s. cJAK is expressed predominantly in thymus and spleen, with lower levels in kidney, thyroid and liver. cJAK is also expressed at low levels in unstimulated splenic Tcells, whereas mRNA levels are increased after activation of the Tcells with Con A. The sequence analysis and pattern of expression suggests that this is an avian homolog of JAK3.
Sofer
L
L
University of Delaware, Department of Animal, Food Sciences, Department of Chemistry, Biochemistry, Newark, DE 19717, USA.
Kampa
D
D
Burnside
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D053616:Janus Kinase 3; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D010802:Phylogeny; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000737:chemistry* / Q000378:metabolism
D018076:DNA, Complementary; D012333:RNA, Messenger; D011505:Protein-Tyrosine Kinases; D053616:Janus Kinase 3