Janus kinase (JAK)

Introduction

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

More general terms

• tyrosine kinase (protein tyrosine kinase, PTK)

More specific terms

• 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)

Additional terms

• cytokine receptor
• signal transducer & activator of transcription (STAT)

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?