期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1991
卷号：88
期号：16
页码：7111-7115
DOI：10.1073/pnas.88.16.7111
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Rat embryo fibroblasts (REF52) exhibit a distinctive, transformation-sensitive distribution of alpha-protein kinase C (alpha-PKC). Receptor-mediated activation of phospholipase C (PLC)-gamma generates diacylglycerol, the major cellular activator of PKC. Immunofluorescence techniques were used to investigate the subcellular localization of two PLC isozymes (PLC-gamma and PLC-delta) in normal and simian virus 40-transformed REF52 cells to determine (i) if PLC colocalizes with alpha-PKC and (ii) if PLC isozyme distribution is sensitive to transformation. PLC-delta was not detected in either cell type. In REF52 cells, PLC-gamma was associated with the actin cytoskeleton and was evenly distributed along the length of the actin microfilaments. PLC-gamma was coincident with alpha-PKC at the points where the filaments are anchored to the membrane (i.e., the focal contacts). Cytoskeletal association of PLC-gamma was not transformation sensitive, although the actin cytoskeleton was more disordered in simian virus 40-transformed cells. In REF52 cells, platelet-derived growth factor induced tyrosine phosphorylation of both soluble and cytoskeletal PLC-gamma. Tyrosine phosphorylation of PLC-gamma did not seem to be a determinant of its subcellular localization, but there was a detectable increase in cytoskeleton-associated PLC-gamma in response to platelet-derived growth factor treatment.
