Visna virus is a pathogenic lentivirus of sheep tat is distantly related to the primate lentiviruses, including human immunodeficiency virus type 1. The visna virus genome encodes a small regulatory protein, Tat, which is necessary for efficient viral replication and enhanced viral transcription. To investigate the mechanism of action of the visna Tat protein and to localize the protein domain(...

The human immunodeficiency virus type 1 (HIV-1) Tat protein enhances reverse transcription, but it is not known whether Tat acts directly on the reverse transcription complex or through indirect mechanisms. Since processing of Tat by HIV protease (PR) might mask its presence and, at least in part, explain this lack of data, we asked whether Tat can be cleaved by PR. We used a rabbit reticulocyt...

PURPOSE To examine the applicability of TAT (the protein transduction domain of transactivating transcription polypeptide)-mediated protein-transduction technology, in introducing proteins of interest into trabecular meshwork (TM) cells in various culture systems. METHODS Normal human TM cell cultures, human tissues in organ cultures, and bovine eyes in perfusion organ cultures were incubated...

The transactivator protein of human immunodeficiency virus type 1 (HIV-1) (Tat) is a powerful activator of nuclear factor-kappaB (NF-kappaB), acting through degradation of the inhibitor IkappaB-alpha (F. Demarchi, F. d'Adda di Fagagna, A. Falaschi, and M. Giacca, J. Virol. 70:4427-4437, 1996). Here, we show that this activity of Tat requires the function of the cellular interferon-inducible pro...

We determined immune cross-recognition and the degree of Tat conservation in patients infected by local human immunodeficiency virus (HIV) type 1 strains. The data indicated a similar prevalence of total and epitope-specific anti-Tat IgG in 578 serum samples from HIV-infected Italian (n=302), Ugandan (n=139), and South African (n=137) subjects, using the same B clade Tat protein that is being u...

Human immunodeficiency viruses HIV-1 and HIV-2 encode a Tat protein that trans-activates the respective viral genome through RNA targets (TAR1 and TAR2). Tat-1 and Tat-2 have considerable homology. However, an interesting biological observation has been that Tat-1 activates the HIV-1 and HIV-2 LTRs equally while Tat-2 activates the former, in comparison to the latter, poorly. Here, we present e...

Human immunodeficiency virus-1 (HIV-1)-encoded transactivator of transcription (Tat) potentiated the depolarization-evoked exocytosis of [(3)H]D-aspartate ([(3)H]D-ASP) from human neocortical terminals. The metabotropic glutamate (mGlu) 1 receptor antagonist 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester (CPCCOEt) prevented this effect, whereas the mGlu5 receptor antagonist 2-m...

Human immunodeficiency virus-1 tat (HIV-tat) protein, like other proinflammatory cytokines (such as TNF), activates a wide variety of cellular responses, some of which play a critical role in progression of HIV infection. Whether HIV-tat, like TNF, also activates c-Jun N-terminal kinase (JNK) and the transcription factor activator protein (AP)-1 is not known. We show that treatment of human his...

BACKGROUND Adherence interventions in psychotic disorders have produced mixed results. Even when an intervention improved adherence, benefits to patients were unclear. Treatment Adherence Therapy (TAT) also improved adherence relative to Treatment As Usual (TAU), but it had no effects on symptoms or quality of life. TAT may or may not reduce healthcare costs. AIM To determine whether TAT redu...

OBJECTIVE The region of the 110 kDa regulatory subunit (MYPT1) of smooth muscle myosin phosphatase involved in the regulation of contraction was determined under physiological conditions. METHODS AND RESULTS Using HIV Tat protein-mediated protein transduction, the N-terminal fragments of MYPT1 were introduced to the intact porcine coronary arterial strips. Pre-incubation with 3 micromol/L TAT...