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Identification of a Major Protein on the Cytosolic Face of Caveolae

J Vinten, A H Johnsen, P Roepstorff, J Harpøth, J Tranum-Jensen

Biochim Biophys Acta. 2005 Nov 10;1717(1):34-40.

PMID: 16236245

Abstract:

Cav-p60, a specific and ubiquitous caveolar protein, was immunoprecipitated from solubilized rat adipocyte plasma membranes and identified as similar to a GeneBank entry annotated mouse polymerase transcript release factor (PTRF) by MALDI-TOF and MS-MS of major fragments. Cloning and virtual translation of the corresponding rat adipocyte cDNA sequence revealed 98.7% identity with mouse PTRF. In vitro translation of this sequence produced a protein, which was recognized by antibodies to both cav-p60 and PTRF. EM gold labeling studies showed that a rabbit antiserum against murine PTRF immunolabeled caveolae specifically in adipocytes from both mouse and rat. In view of the reported function of the protein, which is exerted in the cell nucleus, its subcellular localization was investigated. We found that the protein could be purified by differential solubilization of a plasma membrane fraction followed by SDS-PAGE, and that the protein was as abundant as caveolin in this fraction. We were unable to detect the protein in cell nuclei by subcellular fractionation or fluorescence microscopy. The results show that in a large number of cell types, PTRF is essentially located to caveolae, and that each caveola harbors many copies of the protein. Consequently, we suggest the name Cavin for this protein.

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Catalog Number Product Name Structure CAS Number Price
IAR42416802 Anti-phospho-Neutrophil Cytosol Factor 1 (pSer328) antibody produced in rabbit Anti-phospho-Neutrophil Cytosol Factor 1 (pSer328) antibody produced in rabbit Price
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