Substrate-Length-Dependent Activities of Human Immunodeficiency Virus Type 1 Integrase in Vitro: Differential DNA Binding Affinities Associated with Different Lengths of Substrates

Biochemistry ◽  
1995 ◽  
Vol 34 (32) ◽  
pp. 10215-10223 ◽  
Author(s):  
S. Paul Lee ◽  
Michael L. Censullo ◽  
Hyun G. Kim ◽  
Myun K. Han
2002 ◽  
Vol 76 (16) ◽  
pp. 8019-8030 ◽  
Author(s):  
Norio Takada ◽  
Takaomi Sanda ◽  
Hiroshi Okamoto ◽  
Jian-Ping Yang ◽  
Kaori Asamitsu ◽  
...  

ABSTRACT RelA-associated inhibitor (RAI) is an inhibitor of nuclear factor κB (NF-κB) newly identified by yeast two-hybrid screen as an interacting protein of the p65 (RelA) subunit. In this study, we attempted to examine the effect of RAI on transcription and replication of human immunodeficiency virus type 1 (HIV-1). We found that RAI inhibited gene expression from the HIV-1 long terminal repeat (LTR) even at the basal level. Upon in vitro DNA-binding reactions, RAI could directly block the DNA-binding of p65 subunit of NF-κB but not that of the p50 subunit or AP1. We found that RAI could also inhibit the DNA-binding of Sp1 and thus inhibit the basal HIV-1 promoter activity. We further examined the effects of RAI on Sp1 and found that RAI colocalizes with Sp1 in the nucleus and interacts with Sp1 in vitro and in vivo. Moreover, we found that RAI efficiently blocked the HIV-1 replication when cotransfected with a full-length HIV-1 clone. These findings indicate that RAI acts as an efficient inhibitor of HIV-1 gene expression in which both NF-κB and Sp1 play major roles.


2017 ◽  
Vol 15 (10) ◽  
pp. 917-933 ◽  
Author(s):  
Jacobo Lopez-Abente ◽  
Adrián Prieto-Sanchez ◽  
Maria-Ángeles Muñoz-Fernandez ◽  
Rafael Correa-Rocha ◽  
Marjorie Pion

2002 ◽  
Vol 76 (3) ◽  
pp. 1015-1024 ◽  
Author(s):  
Barbara Müller ◽  
Tilo Patschinsky ◽  
Hans-Georg Kräusslich

ABSTRACT The Gag-derived protein p6 of human immunodeficiency virus type 1 (HIV-1) plays a crucial role in the release of virions from the membranes of infected cells. It is presumed that p6 and functionally related proteins from other viruses act as adapters, recruiting cellular factors to the budding site. This interaction is mediated by so-called late domains within the viral proteins. Previous studies had suggested that virus release from the plasma membrane shares elements with the cellular endocytosis machinery. Since protein phosphorylation is known to be a regulatory mechanism in these processes, we have investigated the phosphorylation of HIV-1 structural proteins. Here we show that p6 is the major phosphoprotein of HIV-1 particles. After metabolic labeling of infected cells with [ortho- 32P]phosphate, we found that phosphorylated p6 from infected cells and from virus particles consisted of several forms, suggesting differential phosphorylation at multiple sites. Apparently, phosphorylation occurred shortly before or after the release of p6 from Gag and involved only a minor fraction of the total virion-associated p6 molecules. Phosphoamino acid analysis indicated phosphorylation at Ser and Thr, as well as a trace of Tyr phosphorylation, supporting the conclusion that multiple phosphorylation events do occur. In vitro experiments using purified virus revealed that endogenous or exogenously added p6 was efficiently phosphorylated by virion-associated cellular kinase(s). Inhibition experiments suggested that a cyclin-dependent kinase or a related kinase, most likely ERK2, was involved in p6 phosphorylation by virion-associated enzymes.


2003 ◽  
Vol 77 (1) ◽  
pp. 291-300 ◽  
Author(s):  
L. Musey ◽  
Y. Ding ◽  
J. Cao ◽  
J. Lee ◽  
C. Galloway ◽  
...  

ABSTRACT Induction of adaptive immunity to human immunodeficiency virus type 1 (HIV-1) at the mucosal site of transmission is poorly understood but crucial in devising strategies to control and prevent infection. To gain further understanding of HIV-1-specific T-cell mucosal immunity, we established HIV-1-specific CD8+ cytotoxic T-lymphocyte (CTL) cell lines and clones from the blood, cervix, rectum, and semen of 12 HIV-1-infected individuals and compared their specificities, cytolytic function, and T-cell receptor (TCR) clonotypes. Blood and mucosal CD8+ CTL had common HIV-1 epitope specificities and major histocompatibility complex restriction patterns. Moreover, both systemic and mucosal CTL lysed targets with similar efficiency, primarily through the perforin-dependent pathway in in vitro studies. Sequence analysis of the TCRβ VDJ region revealed in some cases identical HIV-1-specific CTL clones in different compartments in the same HIV-1-infected individual. These results clearly establish that a subset of blood and mucosal HIV-1-specific CTL can have a common origin and can traffic between anatomically distinct compartments. Thus, these effectors can provide immune surveillance at the mucosa, where rapid responses are needed to contain HIV-1 infection.


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