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HIV‐1 Tat is unconventionally secreted through the plasma membrane
Author(s) -
Rayne Fabienne,
Debaisieux Solène,
Bonhoure Anne,
Beaumelle Bruno
Publication year - 2010
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1042/cbi20090376
Subject(s) - endoplasmic reticulum , secretion , transfection , intracellular , microbiology and biotechnology , glycosylation , secretory pathway , secretory protein , biology , transport protein , biochemistry , golgi apparatus , gene
The Tat protein is required for efficient HIV‐1 (human immunodeficiency virus type 1) transcription. Moreover, Tat is secreted by infected cells, and circulating Tat can affect several cell types, thereby contributing to HIV‐1 pathogenesis. We monitored Tat secretion by transfected CD4+ T‐cells. A Tat chimaera carrying an N‐glycosylation site did not become glycosylated when expressed in cells, while the chimaera was glycosylated when mechanically introduced into purified microsomes. These data indicate that secreted Tat does not transit through the endoplasmic reticulum. The use of pharmacological inhibitors indicated that the Tat secretion pathway is unusual compared with previously identified unconventional secretion routes and does not involve intracellular organelles. Moreover, cell incubation at 16°C inhibited Tat secretion and caused its accumulation at the plasma membrane, suggesting that secretion takes place at this level.