N-terminal processing and modifications of caveolin-1 in caveolae from human adipocytes
2004 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 320, no 2, 480-486 p.Article in journal (Refereed) Published
Caveolin, the principal structural protein of caveolae membrane domains, has a cytosol-exposed N-terminal part that was cleaved off by trypsin treatment of caveolae vesicles isolated from primary human adipocytes. Sequencing of the released tryptic peptides by nanospray quadrupole time-of-flight mass spectrometry revealed that both caveolin-1alpha and caveolin-1beta were processed by excision of the starting methionines. The N-terminus of the mature caveolin-1alpha was acetylated, while caveolin-1beta was found in acetylated as well as in non-acetylated forms. Fractional phosphorylation of serine-36 in the mature caveolin-1alpha and of the homologous serine-5 in caveolin-1beta was identified. This is the first experimental evidence for in vivo phosphorylation of caveolin-1 at the consensus site for phosphorylation by protein kinase C. The phosphorylation was found in both the acetylated and non-acetylated variants of caveolin-1beta. This variability in modifications is consistent with critical involvement of the N-terminal domain of caveolin in the regulation of caveolae.
Place, publisher, year, edition, pages
2004. Vol. 320, no 2, 480-486 p.
Human adipocyte, Caveolin-1; Caveolae, Protein phosphorylation, N-terminal acetylation, Mass spectrometry
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-19146DOI: 10.1016/j.bbrc.2004.05.196PubMedID: 15219854OAI: oai:DiVA.org:liu-19146DiVA: diva2:223380