Calreticulin: not just another calcium-binding protein.
In this paper we review some of the rapidly expanding information about calreticulin, a Ca(2+)-binding/storage protein of the endoplasmic reticulum. The emphasis is placed on the structure and function of calreticulin. We believe that calreticulin is a multifunctional Ca(2+)-binding protein and that distinct functional properties of the protein may be localized to each of the three structural domains of calreticulin. Most evidence indicates that calreticulin is a resident endoplasmic reticulum protein. However, it can also be found outside of the endoplasmic reticulum compartment, i.e. in the nuclear envelope, in the nucleus, in the cytotoxic granules in T-lymphocytes and in acrosomal vesicles of sperm cells. The evidence reviewed here clearly suggests that calreticulin has other functions in addition to its role as a Ca2+ storage protein in the endoplasmic reticulum.
Nash
P D
PD
Department of Biochemistry, University of Alberta, Edmonton, Canada.
Opas
M
M
Michalak
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000737:chemistry / Q000502:physiology; D001692:Biological Transport / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D037282:Calreticulin; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012261:Ribonucleoproteins / Q000737:chemistry / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship
D001324:Autoantigens; D002135:Calcium-Binding Proteins; D037282:Calreticulin; D012261:Ribonucleoproteins