TAT complex

To determine which amino acids promoted specific TAR—Tat complex formation, a series of peptide mutants were prepared and their dynamic signatures collected (Edwards et al., 2005). Figure 15.1 IB shows the sequence of the peptides and the changes in spectral width for U38 upon... 

The adsorption of the thrombin-antithrombin (TAT) complex on the polymer surface was also examined in plasma. The study was conducted as the AT adsorption was and the results are reported in Fig. 3 for normal plasma and defibrinated plasma. No significant differences can be seen between the two sets of experiments which... 

In previous papersl> the antithrombic activity of these polymers was demonstrated to involve one (or several) plasma cofactor as for instance antithrombin III. The catalytic effect of the polymers on the thrombin-AT reaction was evaluated by comparison of the TAT amounts generated during 10 seconds in presence or absence of polymer. In each case, the polymer suspension - or buffer - was first incubated with fresh platelet poor plasma. Then thrombin was introduced and after 10 seconds the reaction was blocked by addition of hirudin. The Fig. 5 shows a typical variation of TAT generation as a function of the amount of polymer present in the test. The TAT levels were measured in the supernatant bbtained by centrifugation of the final suspension and the results are expressed in percent of the maximum.of TAT complex which can be... 

The comparison of the pol3mier affinities for the different proteins and the TAT complex might suggest a possible mechanism for the catalysis of the TAT generation. When incubated with the polymer, thrombin and AT adsorb on the surface and a fast reaction between the adsorbed species occurs. The TAT complex generated on the insoluble material may be desorbed either by thrombin which has a higher affinity than TAT for the polymer or by albumin which has a lower affinity but is in much larger concentration than TAT complex in plasma. Therefore a catalytic effect can be observed. 

Garcia-Martinez LF, Mavankal G, Neveu JM, Lane WS, Ivanov D, Gaynor RB (1997) Purification of a Tat-associated kinase reveals a TFIIH complex that modulates HIV-1 transcription. 

Mahmoudi T, Parra M, Vries RG, Kauder SE, Verrijzer CP, Ott M, Verdin E (2006) The SWI/SNF chromatin-remodeling complex is a cofactor for Tat transactivation of the HIV promoter. J Biol... 

Treand C, du Chene I, Bres V, Kieman R, Benarous R, Benkirane M, Emdiani S (2006) Requirement for SWI/SNF chromatin-remodeling complex in Tat-mediated activation of the HIV-1 promoter. EMBO J 25(8) 1690-1699... 

Huq, I., Tamilarasu, N., and Rana, T.M. (1999) Visualizing tertiary folding of RNA and RNA-protein interactions by a tethered iron chelate analysis of HIV-1 Tat-TAR complex. Nucleic Acids Res. 27, 1084-1093. 

Rodrigue, A., Chanal, A., Beck, K., Muller, M., and Wu, L.-F. (1999). Co-translocation of a periplasmic enzyme complex by a hitchhiker mechanism through the bacterial TAT pathway. / Biol. Chem. 274, 13223-13228. 

The CSN3 subunit interacts with IKKy, a component of the IsrB-kinase complex controlling NF-kB activity [32]. Additionally, it is the binding site for the CSN-associated kinases CK2 and PKD [31]. The subunit of the translation-initiation factor 3 complex, Int6/eIF3e, and the ubiquitin-conjugating enzyme variant, COPIO, have been identified as other cellular interactors [33, 34]. Also the HIV-1 Tat protein interacts with CSN 3 (our unpublished data). 

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