ISSN:
1573-4919
Keywords:
CaM-stimulated phosphatase isozymes
;
PP2B
;
calcineurin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Molecular cloning of human, mouse and rat brain CaM-stimulated phosphatase has suggested the existence of two genes for the α subunit of the enzymes. Aα and Aβ fragments of Aα and Aβ from rat brain library have been expressed in bacteria to produce specific anti-calcineurin Aα and anti-calcineurin Aβ antibodies (Kunoet al., J Neurochem 58: 1643–1651, 1992). Alternative mRNA splicing gives rise to additional calcineurin isozymes with some containing an insertion sequence of ATVEAIEADE. Antibody against synthetic peptide of this insertion sequence has been raised in this study. Three CaM-stimulated phosphatase isozymes previously purified from bovine brain (BPI, BPII, BPIII) (Yokoyama & Wang, J Biol Chem 266: 14822–14829, 1991), along with the bacterially expressed rat Aα and Aβ fragments, were analyzed by two calcineurin α subunit monoclonal antibodies VJ6 and VD3, the rat anti-calcineurin Aα and anti-calcineurin Aβ specific polyclonal antibodies, and the insertion peptide antibody. The bovine brain CaM-stimulated phosphatase isozymes BPI and BPIII reacted with both anti-calcineurin Aα and anti-calcineurin Aβ antibodies. While BPII reacted with anti-calcineurin Aα but not anti-calcineurin Aβ antibody, it differed from the expressed Aα fragment in immunoreactivity towards the monoclonal antibodies. The results show that the bovine brain CaM-stimulated phosphatase isozymes cannot be simply categorized as derived from Aα or Aβ genes products. On the other hand, on the basis of immunoreactivity toward the insertion antibody, the isozymes can be readily classified into those containing the insertion sequence (BPI, LPI) and those without the inserting (BPII, BPIII, LPII, LPIII).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00926918
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