Synergistic Activation of JAK1 and JAK2 and Functional Characterization in Hematopoietic Progenitor Cells

• Main Authors: Yi-Li Lin, 林宜豊
• Other Authors: Huei-Mei Huang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/60077552107798024493

碩士 === 台北醫學院 === 細胞及分子生物研究所 === 90 === Cytokines are able to induce various signaling pathways during hematopoiesis. Janus kinases (JAKs) were found to play a very important role in some signaling pathways. In most cases, more than one JAK will be simultaneously activated by specific cytokine. However, it is not clear that how simultaneous activated-JAKs can affect cellular activity. Our previous results have shown that phosphorylation signaling, including tyrosine phosphorylation of STAT5, MAPK and Akt, can be detected in hematopoietic progenitor cells co-transfected with JAK1 and JAK2. In present study, one of JAKs was replaced by JAK1 or JAK2 inactive mutants (KE). The resulted two cell lines, Ba/F3-JAK1KE+2 and Ba/F3-JAK1+2KE, respectively, indeed produce either inhibited or reduced phosphorylation profiles of STAT5, MAPK and Akt, as well as proliferation activity of cells. Furthermore, it is indicated that synergistic activated—JAK1 and —JAK2 may associate with receptors and form complexes to pass signals to downstream components of pathway. These results show that both JAK1 and JAK2 need to be activated to produce synergistic effect for signal transduction and cellular proliferation.