Janus kinase (JAK)

Janus is the Roman god of gates & doorways. JAK, An acronym for Just Another Kinase. Function: - JAKs associate with & convey the signals of cytokine receptors - JAKs interact with membrane proximal box1 & box2 motifs on the cytokine receptors & become activated with aggregation of cytokine receptors - cross phosphorylation of JAKs secondary to cytokine receptor & JAK aggregation contributes to JAK activation - the JAKS also phosphorylate the cytokine receptors to form pTyr site which specifically bind SH2 domains of STAT proteins

Related

cytokine receptor signal transducer & activator of transcription (STAT)

Specific

Janus kinase 1 (tyrosine-protein kinase JAK1, JAK-1, JAK1, JAK1A, JAK1B) Janus Kinase 2 (JAK2) Janus kinase 3 (tyrosine-protein kinase JAK3, JAK-3, leukocyte janus kinase, L-JAK) (JAK3) proto-oncogene tyrosine kinase FER (p94-FER, c-FER, tyrosine kinase 3, fer (fps/fes related) tyrosine kinase, FER TYK3) tyrosine kinase TYK2 (TYK2)

Properties

STATE: active state MOTIF: Tyr phosphorylation site kinase domain MOTIF: ATP-binding site NAME: ATP-binding site binding site FOR-BINDING-OF: cytokine receptor FOR-BINDING-VIA: box1 motif binding site FOR-BINDING-OF: cytokine receptor FOR-BINDING-VIA: box2 motif

References

- Ihle JN et al Signaling by the cytokine receptor superfamily: JAKs and STATs TIBS 19:222 1994 PMID: 8048164