The extracellular activities of the human immunodeficiency virus (HIV) transactivator protein (Tat) include induction of angiogenesis and stimulation of monocyte migration. Here it is shown that polymorphonuclear leukocytes (PMNL), mostly neutrophils, rapidly invade in response to Tat in vivo and initiate the formation of new vessels. In vitro, Tat was chemotactic for PMNL and induced calcium (...

The Tat (twin-arginine translocation) system mediates export of periplasmic proteins in folded conformation. Proteins transported via Tat contain a characteristic twin-arginine motif in their signal peptide. Genetic determinants (tatABC genes) of the Tat system from Rhizobium leguminosarum bv. viciae were cloned and characterized, and a tatBC deletion mutant was constructed. The mutant lacked t...

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 mol/L TAT-MYPT1,...

The twin arginine translocation (Tat) pathway transports folded proteins across the cytoplasmic membrane of bacteria. Tat signal peptides contain a consensus motif (S/T-R-R-X-F-L-K) that is thought to play a crucial role in substrate recognition by the Tat translocase. Replacement of the phenylalanine at the +2 consensus position in the signal peptide of a Tat-specific reporter protein (TorA-Ma...

Cloning and sequencing of a lipase gene from an indigenous Bacillus pumilus, strain F3, revealed an open-reading frame of 648 nucleotides predicted to encode a protein of 215 residues. Sequence analysis showed that F3 lipase contained a signal peptide composed of 34 amino acids with an H domain of 18 residues. A tat-like motif was found in the signal peptide similar to some other Bacillus pumil...

Optimized delivery of antigens combined with sustainable maturation of dendritic cells (DCs) is crucial for generation of effective antitumoral immune responses. Multiple approaches for ex vivo antigen loading and improvement in immunogenicity have been described. We have recently established a single-step protocol consisting of a fusion peptide (a sequence of the melanoma antigen Melan-A and a...

The twin arginine translocation (Tat) system transports folded proteins across the bacterial plasma membrane. In Gram-negative bacteria, membrane-bound TatABC subunits are all essential for activity, whereas Gram-positive bacteria usually contain only TatAC subunits. In Bacillus subtilis, two TatAC-type systems, TatAdCd and TatAyCy, operate in parallel with different substrate specificities. He...

The purified human immunodeficiency virus type-l (HIV-l) Tat protein inhibited lymphocyte proliferation induced by tetanus toxoid or Candida antigens by 66 to 97% at nanomolar concentrations of Tat. In contrast, Tat did not cause a significant reduction of lymphocyte proliferation in response to mitogens such as phytohemagglutinin or pokeweed mitogen. Inhibition was blocked by oxidation of the ...

In this study, a cell-penetrating peptide, the transactivating transcriptional factor (TAT) domain from HIV, was linked to a chitosan/doxorubicin (chitosan/DOX) conjugate to form a chitosan/DOX/TAT hybrid. The synthesized chitosan/DOX/TAT conjugate showed a different intracellular distribution pattern from a conjugate without TAT. Unlike both free DOX and the conjugate without TAT, the chitosan...

We have performed molecular dynamics (MD) simulations, with particle-mesh Ewald, explicit waters, and counterions, and binding specificity analyses using combined molecular mechanics and continuum solvent (MM-PBSA) on the bovine immunodeficiency virus (BIV) Tat peptide-TAR RNA complex. The solution structure for the complex was solved independently by Patel and co-workers and Puglisi and co-wor...