Signal transducer and activator of transcription 5 (322-343) acetylamide, (C115H193N27O33), a peptide with the sequence Ac-DIISALVTSTFIIEKQPPQVLK-amide, MW= 2481.92. The STAT protein (Signal Transducer and Activator of Transcription) regulates many aspects of growth, survival and differentiation in cells. STAT5 refers to two highly related proteins, STAT5A and STAT5B, which are encoded by separate genes, but are 90% identical at the amino acid level (1). This protein is a member of the STAT family of transcription factors. In response to cytokines and growth factors, STAT family members are phosphorylated by the receptor associated kinases, and then form homo- or heterodimers that translocate to the cell nucleus where they act as transcription activators(2). This protein is activated by, and mediates the responses of many cell ligands, such as IL2, IL3, IL7 GM-CSF, erythropoietin, thrombopoietin, and different growth hormones. Activation of this protein in myeloma and lymphoma associated with a TEL/JAK2 gene fusion is independent of cell stimulus and has been shown to be essential for the tumorigenesis(3).
Figure1 structure of Signal transducer and activator of transcription5A
Figure2 signal pathway of STAT5
Ref:
1. Grimley PM, Dong F, Rui H (June 1999). "Stat5aand Stat5b: fraternal twins of signal transduction and transcriptional activation". Cytokine Growth Factor Rev. 10 (2): 131–57.
2. Hou J, Schindler U, Henzel WJ, Wong SC, McKnight SL (May 1995). "Identification and purification of human Stat proteins activated in response to interleukin-2". Immunity 2 (4): 321–9.
3. Kisseleva T, Bhattacharya S, Braunstein J, Schindler CW (2002). "Signaling through the JAK/STAT pathway, recent advances and future challenges.". Gene 285 (1-2): 1–24.