Acylated simian virus 40 large T-antigen: a new subclass associated with a detergent-resistant lamina of the plasma membrane.
We have analyzed the plasma membrane association of the SV40 large tumor antigen (large T) in SV40-transformed BALB/c mouse tumor cells (mKSA). Isolated plasma membranes were subfractionated: treatment with the non-ionic detergent Nonidet P40 (NP40) resulted in a NP40-resistant plasma membrane lamina, which could be further extracted with the zwitterionic detergent Empigen BB. Analysis of the different plasma membrane fractions revealed that only about one third of large T associated with isolated plasma membranes could be solubilized with NP40. The residual plasma membrane-associated large T was tightly bound to the NP40-resistant lamina of the plasma membrane from which it was released by treatment with the zwitterionic detergent Empigen BB. Further evidence for a specific interaction of a distinct subclass of large T with the plasma membrane was provided by showing that only T associated with the NP40-resistant lamina of the plasma membrane contained covalently bound fatty acid. Neither nuclear large T nor large T in the NP40-soluble plasma membrane fraction could be labeled with [3H]palmitic acid. Our results indicate that an acylated subclass of large T interacts specifically with a structure of the plasma membrane, suggesting that it might be involved in a membrane-dependent biological function.
D000215:Acylation; D000818:Animals; D000957:Antigens, Viral, Tumor / Q000145:classification*; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology*; D002472:Cell Transformation, Viral; D003902:Detergents / Q000494:pharmacology; D051379:Mice; D013539:Simian virus 40 / Q000276:immunology*
D000957:Antigens, Viral, Tumor; D003902:Detergents