JAK - STAT Pathway

JAK - STAT Pathway 

JAK - STAT Pathway

Full form: Janus - Kinase Signal Transducer and Activator of Transcription Pathway

Definition:

It is a pathway that transmits information from chemical signals outside the cell,  which causes DNA transcription and other activity in the cell.

Components:

3 main components -

a. A receptor

b. Janus - Kinase (JAK)

c. Signal Transducer and Activator of Transcription (STAT)

Mechanism:

1. JAK has tyrosine kinase activity, binds to some cell surface cytokine receptors.

2. The binding of the ligand to the receptor triggers activation of JAKs.

3. With increased kinase activity, they phosphorylate tyrosine residues on the receptor.

STATs possessing SH2 domains are recruited to the receptors.

4. Then they are tyrosine phosphorylated by JAKs on the receptors.

5. Activated STAT dimers accumulate in the cell nucleus and activate transcription of their target genes.

6. STATs may also be tyrosine phosphorylated directly by receptor tyrosine kinases, such as the epidermal growth factor receptor as well as by non-receptor tyrosine kinases.

7. Activated STATs regulate expression of IFN and other cytokine-sensitive genes.

The Daily Youth- tdy24.com Presents

" JAK - STAT Pathway"

Written By

Sadia Akhtar

Student of Department of Microbiology

Jagannath University.

Email- sadiabd810@yahoo.com