Premium
Phosphoinositidase C isozymes in SaOS‐2 cells: Immunocytochemical detection in nuclear and cytoplasmic compartments
Author(s) -
Maraldi Nadir M,
Zini Nicoletta,
Santi Spartaco,
Bavelloni Alberto,
Valmori Aurelio,
Marmiroli Sandra,
Ognibene Andrea
Publication year - 1993
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1016/0248-4900(93)90143-3
Subject(s) - cytoplasm , cytoskeleton , biology , immunocytochemistry , cytosol , nuclear matrix , nucleus , microbiology and biotechnology , cell nucleus , cellular compartment , cell culture , cell , biochemistry , enzyme , endocrinology , genetics , gene , chromatin
Summry— SaOS‐2 cell line presents osteoblastic characteristics which can be modulated by specific agonists involving also phosphoinositide breakdown. In order to determine whether SaOS‐2 cells display a phosphoinositide signalling system not only at the cytosol‐cell membrane level but also, as recently reported for other cell lines, at the nuclear level, a study has been performed to evaluate the phosphoinositidase C (PIC) activity and to localize different isoforms of PIC in nuclear and cytoplasmic compartments. By immunochemicals methods, and by confocal and electron microscope immunocytochemistry, both PIC β 1 and γ 1 have been detected in the nucleus, while only PIC γ 1 was found in the cytoplasm. A specific association with the inner nuclear matrix has been demonstrated for PIC β 1 and γ 1 ; this latter resulted, on the other hand, in relationship with cytoskeletal filaments after high salt extraction. These findings suggest that these enzymes are not completely soluble but functionally related with cytoskeletal and nucleoskeletal structures.