Calreticulin in the heart.
Calreticulin is a Ca2+ binding/storage chaperone resident protein of the endoplasmic reticulum. This protein plays a key role in the calreticulin/calnexin cycle and the quality control pathways in the endoplasmic reticulum. Calreticulin deficiency is lethal due to impaired cardiac development. However, over-expression of the protein in developing and postnatal heart leads to bradycardia, complete heart block and sudden death. Ultrastructural evidence indicates that the deficiency associated with the absence of calreticulin in the heart may be due to a defect in the development of the contractile apparatus and/or a defect in development of the conductive system as well as a metabolic abnormality. Collectively, we postulate that calreticulin and endoplasmic reticulum plays an important role in cardiac development and postnatal pathologies.
Michalak
Marek
M
Canadian Institutes of Health Research, Membrane Protein Research Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.
Guo
Lei
L
Robertson
Murray
M
Lozak
Mira
M
Opas
Michal
M
D000818:Animals; D037282:Calreticulin / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005318:Fetal Heart / Q000378:metabolism; D015870:Gene Expression; D006321:Heart / Q000254:growth & development; D006327:Heart Block / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D008854:Microscopy, Electron; D008958:Models, Molecular; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure
D037282:Calreticulin