Calreticulin is the major Ca2+ storage protein in the endoplasmic reticulum of the pea plant (Pisum sativum).
A 56kDa protein with high similarity in its N-terminal amino acid sequence to animal calreticulin and 100% homology with the N-terminal amino acids of spinach calreticulin has been identified in seeds of the pea plant (Pisum sativum). A new purification procedure is described by which the calreticulin-like protein was selectively solubilized by incubation with deoxycholate and HgCl2 from microsomes enriched for endoplasmic reticulum. Following Mono Q ion exchange chromatography of the deoxycholate extract by fast protein liquid chromatography, the calreticulin-like protein was obtained in nearly pure form. This purified protein is similar to animal calreticulin in apparent mass, characteristic blue staining with Stains-all dye and calcium-binding ability. In addition, this protein is recognized only by affinity purified antibodies against rabbit calreticulin and is not recognized by anti-calsequestrin antibodies. Our data suggested that calreticulin rather than calsequestrin functions as the Ca(2+)-storage protein in the endoplasmic reticulum of pea plants.
Hassan
A M
AM
Dept. of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Moscow 83844, USA.
Wesson
C
C
Trumble
W R
WR
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D037282:Calreticulin; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000378:metabolism*; D011817:Rabbits; D012261:Ribonucleoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D002135:Calcium-Binding Proteins; D037282:Calreticulin; D012261:Ribonucleoproteins; D002118:Calcium