PT  - JOURNAL ARTICLE
AU  - Neame, S.J.
AU  - Uff, C.R.
AU  - Sheikh, H.
AU  - Wheatley, S.C.
AU  - Isacke, C.M.
TI  - CD44 exhibits a cell type dependent interaction with triton X-100 insoluble, lipid rich, plasma membrane domains
DP  - 1995 Sep 01
TA  - Journal of Cell Science
PG  - 3127--3135
VI  - 108
IP  - 9
4099  - http://jcs.biologists.org/content/108/9/3127.short
4100  - http://jcs.biologists.org/content/108/9/3127.full
SO  - J. Cell Sci.1995 Sep 01; 108
AB  - CD44 is an abundant, widely expressed transmembrane glycoprotein which can act as a receptor for the extracellular matrix glycosaminoglycan, hyaluronan. Biochemical and morphological studies have demonstrated that in fibroblasts a significant of the CD44 population is resistant to Triton X-100 extraction and that the detergent insoluble protein is co-localized with components of the cortical cytoskeleton. Surprisingly, this distribution is not abrogated upon deletion of the CD44 cytoplasmic tail indicating that mechanisms other than a direct interaction with the cytoskeleton can regulate CD44. In this manuscript, the mechanisms underlying this detergent-insoluble association are further investigated. There was no evidence that the Triton X-100 insolubility of CD44 resulted from homotypic aggregation, an association with hyaluronan or from a direct, or indirect, association with the cytoskeleton. Instead, evidence is presented that the detergent insolubility of fibroblast CD44 at 4 degrees C results from an association of the CD44 transmembrane domain with Triton X-100 resistant, lipid rich, plasma membrane domains. The proportion of the CD44 found in these Triton X-100 insoluble structures is dependent upon cell type and cannot be altered by changing cell motility or extracellular matrix associations. These studies provide evidence for a novel mechanism regulating this adhesion protein in the plasma membrane.