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The Sp1 transcription factor does not directly interact with the HIV‐1 Tat protein
Author(s) -
Loregian Arianna,
Bortolozzo Katia,
Boso Silvia,
Sapino Barbara,
Betti Monica,
Biasolo Maria A.,
Caputo Antonella,
Palú Giorgio
Publication year - 2003
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.10271
Subject(s) - sp1 transcription factor , yeast , protein–protein interaction , transcription factor , microbiology and biotechnology , biology , in vitro , two hybrid screening , human immunodeficiency virus (hiv) , plasma protein binding , in vivo , computational biology , chemistry , promoter , genetics , gene , gene expression , virology
Abstract The role of Sp1 in regulating the trans‐activating activity of the human immunodeficiency virus type 1 (HIV‐1) Tat protein has not yet been clearly defined. In fact, studies on the physical and functional interaction between Sp1 and Tat have yielded contradictory results. Here we investigated whether a physical interaction between Sp1 and Tat indeed occurs, exploiting both biochemical and genetic techniques that allow detection of direct protein–protein interactions. Studies performed with the yeast two‐hybrid system indicate that Sp1 does not directly interact with the HIV‐1 Tat protein. Control experiments demonstrated that both proteins are functionally expressed in the yeast cells. In vitro binding assays further confirmed that Sp1 does not physically bind Tat. These data suggest that in vivo Tat and Sp1 most likely take part of a multicomponent complex and thus encourage the search of the molecule(s) which mediate Tat–Sp1 interaction. J. Cell. Physiol. 196: 251–257, 2003. © 2003 Wiley‐Liss, Inc.