Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài:" Inhibition of Tat activity by the HEXIM1 protein | Retrovirology BioMed Central Research Inhibition of Tat activity by the HEXIMI protein Alessandro Fraldi1 3 Francesca Varrone1 Giuliana Napolitano1 Annemieke A Michels2 Barbara Majello1 Olivier Bensaude2 and Luigi Lania 1 Open Access Address Department of Structural and Functional Biology University of Naples Federico II Naples Italy 2UMR 8541 CNRS Ecole Normale Supérieure Laboratoire de Regulation de l Expression Génétique Paris France and 3Telethon Institute of Genetics and Medicine TIGEM Naples Italy Email Alessandro Fraldi - fraldi@ Francesca Varrone - Giuliana Napolitano - Annemieke A Michels - michels@ Barbara Majello - Olivier Bensaude - bensaude@ Luigi Lania - lania@ Corresponding author Published 02 July 2005 Received 29 June 2005 Retrovirology 2005 2 42 doi 1742-4690-2-42 Accepted 02 July 2005 This article is available from http content 2 1 42 2005 Fraldi et al licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background The positive transcription elongation factor b P-TEFb composed by CDK9 CyclinT1 subunits is a dedicated co-factor of HIV transcriptional transactivator Tat protein. Transcription driven by the long terminal repeat LTR of HIV involves formation of a quaternary complex between P-TEFb Tat and the TAR element. This recruitment is necessary to enhance the processivity of RNA Pol II from the HIV-1 5 LTR promoter. The activity of P-TEFb is regulated in vivo and in vitro by the HEXIM1 7SK snRNA ribonucleic-protein complex. Results Here we report that Tat transactivation is effectively inhibited by co-expression of HEXIM1 or its paralog HEXIM2. HEXIM1 .
