β-Actin is a downstream effector of the PI3K/AKT signaling pathway in myeloma cells.
Interleukin 6 is the in vivo growth factor of myeloma cells. In response to IL-6 stimulation, the PI3K/AKT signaling pathway is activated in these cells. With comparative proteomic approaches, this study reveals many putative downstream effectors of the PI3K/AKT pathway. Mass spectrometry analysis of excised protein spots from 2-dimensional gel allowed the identification of proteins such as β-Actin, cyclophilin A, E3 SUMO-protein ligase PIAS-NY protein, HSP 27, PML, and transforming growth factor β-2. Among these putative effectors, β-Actin was chosen for further characterization. Phosphorylation of β-Actin by AKT upon IL-6 stimulation was confirmed by western blotting using a phospho-AKT substrate antibody. Interestingly, IL-6 significantly increased cell migration (P < 0.05) and the content of filamentous actin (P < 0.05). Therefore, IL-6 stimulation could have effects on the migration of myeloma cells, and the phosphorylation of β-Actin is probably involved in the process.
Department of Chemistry and Institute of Chemistry, National Dong Hwa University, Hualien, Taiwan.
Yen-Peng
YP
Ho
Chi-Wei
CW
Kuo
Yuan-Tong
YT
Hsu
Yu-Shan
YS
Huang
Li-Ping
LP
Yew
Wei-Feng
WF
Huang
Kuo-Chih
KC
Lin
Jung-Hsin
JH
Hsu
D000199:Actins / Q000378:metabolism*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement; D015180:Electrophoresis, Gel, Two-Dimensional; D057809:HEK293 Cells; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D009101:Multiple Myeloma / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D040901:Proteomics / Q000379:methods; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000199:Actins; D015850:Interleukin-6; D011994:Recombinant Proteins; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt