Deletion of one of the duplicated Hsp70 genes causes hereditary myopathy of diaphragmatic muscles in Holstein-Friesian cattle.
Heat-shock protein 70 (Hsp70) is a major chaperone that folds protein and prevents aggregation. The Hsp70 family contains both constitutive and stress-inducible forms. In humans, two of the inducible Hsp70 genes are located within the human major histocompatibility complex (MHC) on 6p21.3, as a duplicated locus, 12 kb apart from each other. We report that loss of one of the duplicated Hsp70 genes, the bovine homologue within the bovine MHC, is responsible for hereditary myopathy of diaphragmatic muscles (HMDM) in Holstein-Friesian cattle. Although the remaining Hsp70 gene is intact, Hsp70 protein levels are dramatically decreased in affected cattle. In normal diaphragmatic muscle, Hsp70 binds several proteins involved in energy metabolism including glycogen phosphorylase (PYGM). Immunohistochemical staining indicated that PYGM accumulated in the HMDM-specific core-like structures in affected cattle. Misfolding of energy-related proteins due to Hsp70 deficiency might lead to protein aggregation and muscle fibre degeneration.
Sugimoto
M
M
National Livestock Breeding Center, Nishigo, Fukushima, Japan.
Furuoka
H
H
Sugimoto
Y
Y
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002417:Cattle / Q000235:genetics*; D002846:Chromatography, Affinity; D002874:Chromosome Mapping; D003964:Diaphragm / Q000002:abnormalities*; D017353:Gene Deletion; D024981:Glycogen Phosphorylase / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics*; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009135:Muscular Diseases / Q000662:veterinary*; D017422:Sequence Analysis, DNA
D018840:HSP70 Heat-Shock Proteins; D024981:Glycogen Phosphorylase