Caveolae are specialized membrane invaginations of 50-100 nm present in all cells, but abundant in endothelium, muscle cells, and adipocytes. These plasma membrane microdomains function in transcytosis of macromolecules, and are the sites of potocytosis, where small molecules are concentrated and transferred inside the cells by glycosylphosphatidylinositol (GPI)-linked receptors. Caveolin, a 22kDa protein and a well known marker for these plasma membrane microdomains, plays a structural role in these specializations. Flotillin-1 was isolated from the Triton X-100 insoluble buoyant fraction, characteristic of caveolae. Although the mRNA expression of both Flotillin-1 and Caveolin is very similar, Caveolin is undetectable in brain, while Flotillin-1 is very abundant. Flotillin-1 is a close homolog of the Epidermal Surface Antigen (ESA/Flotillin-2), which also colocalizes in the caveolae. Thus, Flotillin-1 and its relative ESA/Flotillin-2 are now incorporated into the expanding list of proteins co-localized at the caveolae which includes PKCα, Ras, Rap Src-like kinases, Gαßγ,and GPI-linked receptors.
This antibody is routinely tested by western blot analysis. Other applications were tested at BD Biosciences Pharmingen during antibody development only or reported in the literature.