Tumour necrosis factor alpha-induced adipose-related protein (TIARP): co-localization with caveolin-1.
We previously identified TIARP (TNF(alpha)-induced adipose-related protein, where TNF(alpha) stands for tumour necrosis factor alpha), a novel plasma-membrane protein that is induced during 3T3-L1 preadipocytes differentiation by TNF(alpha). Whereas the biological function of TIARP is currently unknown, its protein sequence is reminiscent of transporter protein and/or NAD(P)/NAD(P)H-dependent oxidoreductase activities. We hypothesized that TIARP could be associated with the 3T3-L1 adipocyte plasma-membrane caveolae domains that contain many proteins involved in cellular trafficking and signalling processes. Studies by confocal microscopy showed that TIARP and caveolin-1, a major protein of caveolae, co-localized as patches at the plasma membrane. Immunoblot analysis of cell extracts indicated that TIARP was completely detergent-extractible from membranes, whereas caveolin-1 was present as both detergent-extractible and -insoluble pools. Since TIARP is compartmentalized with caveolin-1 within caveolae domains, we suggest this protein to be part of a signalling complex in association with caveolin-1 and regulatory proteins.
Chambaut-Guérin
Anne-Marie
AM
Laboratoire de Physiologie et Physiopathologie, Centre de Recherche Biomédicale des Cordeliers, UMR 7079 CNRS-Université Paris VI, 15 rue de l'Ecole de Médecine, 75270 Paris Cedex 06, France. guerin@bhdc.jussieu.fr
Pairault
Jacques
J
D041721:3T3-L1 Cells; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D021941:Caveolae / Q000378:metabolism*; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D015398:Signal Transduction / Q000502:physiology
C495541:Cav1 protein, mouse; D051242:Caveolin 1; D022461:Caveolins; D008565:Membrane Proteins; C436323:Tiarp protein, mouse