The Effects of Chimeric G Proteins on the Differentiation of 3T3-L1 Cells

• Main Authors: Yih Nun Lee, 李亦男
• Other Authors: Hsien-yu Wang
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/10666764269219807609

碩士 === 國防醫學院 === 生物化學研究所 === 82 === lly-differentiated mouse 3T3-L1 fibroblast accumulate largeounts of lipid at 7-10 days after induction by hormone cocktailnsulin, dexamethasone and methylisobutylxanthine). Heterotrimeric\βγ) G proteins are invovled in transmembrane signalingocesses from a diverse group of cell-surface receptors torious effector systems including phophoslipase C, adenylylclase and ion channels.The level of G protein markedly changering the differentiation process of 3T3-L1 cells. Applicationantisense DNA of Gsα cDNA fragment accelerated thefferentiation of 3T3-L1 cells.On the other hand stableansfection of Giα2 in 3T3-L1 cells promoted terminalfferentiation to adipocytes.Thus Gsα and Giα2 are shown tocounterregulatory in the promotion of 3T3-L1 fibroblasts tofferentiate into adipocytes.The molecular motif of Gα subunitvolved in cellular differentiation have not been identified.determine the specific domain of Giα2 or Gsα that mediatese regulation of cellular differentiation,we constructed severalprotein chimeras and measured their distinct ability infferentiation.Stable transfection of i/s(38),i(Bam)/s,isi and22/s in 3T3-L1 cells promote differentiation,however, thenfluent s/i and sis clones did not display any adipogenicnversion ability even in the presence of dexmethasone andthylisobutylxanthine.These results indicate that the first 122ino acids residues in N-terminal of Gα subunit is critical ine differentiation of 3T3-L1 to adipocytes.