- 作者: Amber Krause boehm Judith A. Stawhecker O.John Semmes Patrick E. Jankowski Robert Lewis Steven H. Hinrichs
- 作者服務機構: Tax. HTLV-1. Trans-Activation. Phosphorylation. Mutagenesis. Transcription. Genetics
- 中文摘要: --
- 英文摘要: The human T cell leukemia virus type 1(HTLV-1)Tax is aphosphoprotein, however, the contribution of phosphor-ylation to Tax activity is unknown. Previous studies haveshown that phosphorylation of Tax occurs on serine resi-due(s), within one tryptic fragment, in response to 4β-phorbol-12β-myristate-13a-acetate, in both mouse andhuman cells. Studies were conducted in multiple celllines to identify the specific phosphorylated serines as aprelude to functional analysis. The phosphorylation pat-tern of Tax was found to be different in 293T and COS-7cells in comparison with MT-4 and Px-1 cells. However,one tryptic fragment remained consistent in comigrationanalyses among all cell lines.Using selected Tax serinemutants a tryptic fragment containing a serine at residue113 believed to be the site of phosphorylation of Tax didnot comigrate with the common phosphorylated trypticfragment. Analysis of selected Tax mutants for ability totrans-activate the cytomegalovirus promoter demon-strated mutation of serine 77 to a∣anine reduced trans-activation by 90% compared to wild-type Tax. However,examination of the phosphorylation pattern of the serine77 mutant demonstrated that it is not the site of phos-phorylation. These studies demonstrate the importanceof using relevant cell lines to characterize the role ofphosphorylation in protein function.
- 中文關鍵字: --
- 英文關鍵字: --