作者: Peter E. Lobie , Giovanna Allevato , Jens H. Nielsen , Gunnar Norstedt , Nils Billestrup
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摘要: We have examined the involvement of tyrosine residues 333 and 338 growth hormone (GH) receptor in cellular response to GH. Stable Chinese hamster ovary (CHO) cell clones expressing a with at position substituted for phenylalanine (CHO-GHR1-638Y333F, Y338F) were generated by cDNA transfection. Compared wild type Y333F,Y338F mutant possessed normal high affinity ligand binding, internalization, ligand-induced down-regulation. GH activation mitogen-associated protein kinase was also similar CHO number. However, two GH-regulated events (lipogenesis, synthesis) deficient receptor. In contrast, transcriptional regulation (as evidenced chloramphenicol acetyltransferase expression driven GH-responsive region SPI 2.1 gene) not affected substitution. Thus we provide first experimental evidence that specific are required selected responses