Anti-TBCC monoclonal antibody, clone 5D5

The X-linked retinitis pigmentosa protein RP2 is a GTPase activating protein (GAP) for the small GTPase Arl3 and both proteins are implicated in the traffic of proteins to the primary cilia. Here, we show that RP2 can facilitate the traffic of the G beta subunit of transducin (G beta 1). Glutathione S-transferase (GST)-RP2 pulled down G beta from retinal lysates and the interaction was specific to G beta 1, as G beta 3 or G beta 5L did not bind RP2. RP2 did not appear to interact with the G beta:G gamma heterodimer, in contrast G gamma 1 competed with RP2 for G beta binding. Overexpression of G beta 1 in SK-N-SH cells led to a cytoplasmic accumulation of G beta 1, while co-expression of RP2 or G gamma 1 with G beta 1 restored membrane association of G beta 1. Furthermore, RP2 small interfering RNA in ARPE19 cells resulted in a reduction in G beta 1 membrane association that was rescued by G gamma 1 overexpression. The interaction of RP2 with G beta 1 required RP2 N-terminal myristolyation and the co-factor C (TBCC) homology domain. The interaction was also disrupted by the pathogenic mutation R118H, which blocks Arl3 GAP activity. Interestingly, Arl3-Q71L competed with G beta 1 for RP2 binding, suggesting that Arl3-GTP binding by RP2 would release G beta 1. RP2 also stimulated the association of G beta 1 with Rab11 vesicles. Collectively, the data support a role for RP2 in facilitating the membrane association and traffic of G beta 1, potentially prior to the formation of the obligate G beta:G gamma heterodimer. Combined with other recent evidence, this suggests that RP2 may co-operate with Arl3 and its effectors in the cilia-associated traffic of G proteins.

In this study, cotton was bleached at low temperatures with an activated peroxide system which was established by incorporating a bleach activator, namely, N-[4(triethylammoniomethyl)benzoyl]caprolactam chloride (TBCC) into an aqueous solution of hydrogen peroxide (H202). Experimental results showed that the bleaching performance was unexpectedly diminished as the TBCC concentration was increased over the range of 25-100g/L. Kinetic adsorption experiment indicated that this was most likely ascribed to the adsorptive interactions of TBCC and the in situ -generated compounds with cotton fibers. Such a limitation was especially fatal to cold pad -batch bleaching process of cotton in which a high TBCC concentration was often required. The results of this study may stimulate further research to avoid or overcome the limitation of the TBCC-activated peroxide system on low -temperature cotton bleaching. (C) 2015 Elsevier Ltd. All rights reserved.