TY - JOUR
T1 - Maize cap1 encodes a novel SERA-type calcium-ATPase with a calmodulin- binding domain
AU - Subbaiah, Chalivendra C.
AU - Sachs, Martin M.
PY - 2000/7/14
Y1 - 2000/7/14
N2 - A cDNA (CAP1) isolated from maize roots shares sequence identity with genes encoding P-type Ca2+-ATPases and restores the growth phenotype of yeast mutants defective in Ca2+-pumps. CAP1 was transcribed and translated in the yeast mutant. Furthermore, the membrane-integrated product formed a Ca2+-dependent phosphorylated intermediate and supported Ca2+ transport. Although CAP1 shares greater sequence identity with mammalian 'endoplasmic reticulum-type' Ca2+-pumps, it differs from these genes by having features of calmodulin (CaM)-regulated Ca2+-pumps. CAP1 from yeast microsomes bound CaM, and the CAP1-dependent Ca2+ transport in yeast was stimulated by CaM. Peptides from the C terminus of CAP1 bound CaM. Anti-CAP1 antibodies specifically recognized a maize microsomal polypeptide that also bound CaM. A similar polypeptide also formed a Ca2+-dependent phosphoenzyme. Our results suggest that cap1 encodes a novel form of CaM-regulated Ca2+-ATPase in maize. CAP1 appears to be encoded by one or two genes in maize. CAP1 RNA is induced only during early anoxia, indicating that the Ca2+-pump may play an important role in O2-deprived maize cells.
AB - A cDNA (CAP1) isolated from maize roots shares sequence identity with genes encoding P-type Ca2+-ATPases and restores the growth phenotype of yeast mutants defective in Ca2+-pumps. CAP1 was transcribed and translated in the yeast mutant. Furthermore, the membrane-integrated product formed a Ca2+-dependent phosphorylated intermediate and supported Ca2+ transport. Although CAP1 shares greater sequence identity with mammalian 'endoplasmic reticulum-type' Ca2+-pumps, it differs from these genes by having features of calmodulin (CaM)-regulated Ca2+-pumps. CAP1 from yeast microsomes bound CaM, and the CAP1-dependent Ca2+ transport in yeast was stimulated by CaM. Peptides from the C terminus of CAP1 bound CaM. Anti-CAP1 antibodies specifically recognized a maize microsomal polypeptide that also bound CaM. A similar polypeptide also formed a Ca2+-dependent phosphoenzyme. Our results suggest that cap1 encodes a novel form of CaM-regulated Ca2+-ATPase in maize. CAP1 appears to be encoded by one or two genes in maize. CAP1 RNA is induced only during early anoxia, indicating that the Ca2+-pump may play an important role in O2-deprived maize cells.
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U2 - 10.1074/jbc.M001484200
DO - 10.1074/jbc.M001484200
M3 - Article
C2 - 10770930
AN - SCOPUS:0034647919
VL - 275
SP - 21678
EP - 21687
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 28
ER -