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Multiple phosphoinositide‐specific phospholipases C in oat roots: characterization and partial purification
Author(s) -
Huang ChiungHua,
Tate Bonnie F.,
Crain Richard C.,
Coté Gary G.
Publication year - 1995
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1995.08020257.x
Subject(s) - cytosol , phospholipase , biochemistry , phospholipase c , biology , isozyme , enzyme , phosphoinositide phospholipase c , phospholipase a2 , receptor , cell surface receptor , microbiology and biotechnology
Phosphoinositide‐specific phospholipases C are critical enzymes in the transduction of hormonal and environmental signals into animal cells. Several different isozymes of phospholipase C are known in mammalian systems which differ in their expression and regulation. Elucidation of the regulation of these phospholipases C has greatly advanced our understanding of the control of mammalian cell growth and development. Plant cells, too, contain phospholipases C specific for phosphoinositides, and there is evidence that they may be involved in plant cell responses to environmental stimuli. This paper reports that there are at least four variants of phosphoinositide‐specific phospholipase C in the roots of oat seedlings, two cytosolic and two plasma membrane‐associated. The two cytosolic and two plasma membrane variants can be separated on the basis of their affinity for binding to heparin. Both the cytosolic and the plasma membrane heparin‐binding forms have apparent molecular weights of about 50–70 kDa by size exclusion chromatography. The two heparin‐binding forms have been partially purified. The partially purified enzymes are activated by micromolar calcium and are specific for phosphorylated phosphoinositides; in their substrate specificities they resemble mammalian phospholipases C ɛ.