T-cadherin Is a Major Glycophosphoinositol-anchored Protein Associated with Noncaveolar Detergent-insoluble Domains of the Cardiac Sarcolemma
| Autor: | J Upshaw-Earley, Ernest Page, Donald D. Doyle, H. Clive Palfrey, G. E. Goings, Barbara Ranscht |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Caveolin 3
Glycosylphosphatidylinositols Octoxynol Detergents Molecular Sequence Data Muscle Proteins Biology Caveolins Biochemistry Sarcolemma Caveolae Caveolin Animals Myocyte Amino Acid Sequence Molecular Biology Sheep Phospholipase C Myocardium Membrane Proteins Cell Biology Cadherins T-cadherin Microscopy Electron Isoelectric point Solubility Cytoplasm |
| Zdroj: | Journal of Biological Chemistry. 273:6937-6943 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.273.12.6937 |
| Popis: | Sucrose-density flotation analysis of Triton-insoluble membrane domains isolated from highly purified sheep ventricular sarcolemma revealed the presence of two major 120- and 100-kDa proteins. Both species migrated in two-dimensional isoelectric focussing/SDS gels with an apparent pI of approximately 4.3, suggesting that they might be related. Microsequence analysis of peptides derived from the 100-kDa protein yielded amino acid sequences with high homology to T-cadherin, a truncated cadherin lacking a cytoplasmic domain. The similarity was confirmed using antibodies to chicken T-cadherin that reacted with both proteins on immunoblots. T-cadherin was released from the detergent-insoluble sarcolemmal fraction by phospholipase C treatment indicating that it is linked to the membrane by a glycophosphoinositol anchor. T-cadherin could be ADP-ribosylated by a transferase that was also present in the caveolin-enriched Triton-insoluble fraction. T-cadherin-containing membrane fragments cofractionated on sucrose gradients with caveolin-3, a marker protein for myocyte caveolae. However, immunopurified caveolin-3-containing membranes contained no associated T-cadherin. Immunocytochemical analysis of cultured rat atrial myocytes revealed that T-cadherin and caveolin have related but nonoverlapping staining patterns. These results suggest that T-cadherin is a major glycophosphoinositol-linked protein in cardiac myocytes and that it may be located in plasma membrane "rafts" distinct from but possibly adjacent to caveolae. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|