The primary identification of a calcineurin A subunit-like protein in plants.
Many types of serine/threonine protein phosphatase have been cloned and characterized in plants, such as Type-1 serine/threonine protein phosphatase (PP1), Type-2A serine/threonine protein phosphatase (PP2A), Type-2C serine/threonine protein phosphatase (PP2C). However no Type-2B serine/threonine protein phosphatase (PP2B, calcineurin), or calcineurin A subunit-like protein (CaNAL), has been identified. We detected protein phosphatase activity in mixtures of CaM-binding proteins from three plants (Nicotiana tabacum, Brassica oleracea and Arabidopsis thaliana). Two-dimensional electrophoresis (2-D) and Western blot analysis with an anti-rat CNA antibody revealed a small protein of 60 kDa that we believe is a CaNAL. The isoelectric point (pI) of this protein in N. tabacum was approximately 5.69. The protein phosphatase activity in the mixture of CaM-binding proteins from N. tabacum was regulated by Ca(2+) and Calmodulin (CaM) with either RII peptides or pNPP as substrate. The immunosuppressive drugs, CsA and FK506, also inhibited the protein phosphatase activity significantly.
Yang
Chenggang
C
Department of Biochemistry and Molecular Biology, Beijing Normal University, Beijing Key Laboratory, Beijing 100875, China.
Song
Hongtao
H
Weng
Hua
H
Wei
Qun
Q
D017360:Arabidopsis / Q000378:metabolism; D015153:Blotting, Western; D001937:Brassica / Q000378:metabolism; D019703:Calcineurin / Q000302:isolation & purification / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D007526:Isoelectric Point; D010940:Plant Proteins / Q000302:isolation & purification / Q000378:metabolism*; D014026:Nicotiana / Q000378:metabolism
D002148:Calmodulin-Binding Proteins; D010940:Plant Proteins; D019703:Calcineurin