Tumour necrosis factor α-induced adipose-related protein (TIARP): co-localization with caveolin-1

• Published in: Biology of the cell 2005-05, Vol.97 (5), p.339-347
• Main Authors: Chambaut-Guérin, Anne-Marie, Pairault, Jacques
• Format: Article
• Language: English
• Subjects: 3T3-L1; 3T3-L1 Cells; adipocyte; Animals; Biological Transport - physiology; Caveolae - metabolism; caveolin; Caveolin 1; Caveolins - metabolism; cellular trafficking; Membrane Proteins - metabolism; Mice; Signal Transduction - physiology; tumour necrosis factor
• ISSN: 0248-4900; 1768-322X
• DOI: 10.1042/BC20040062

We previously identified TIARP (TNFα‐induced adipose‐related protein, where TNFα stands for tumour necrosis factor α), a novel plasma‐membrane protein that is induced during 3T3‐L1 preadipocytes differentiation by TNFα. 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.