title: Handling of human short-chain acyl-CoA dehydrogenase (SCAD) variant proteins in transgenic mice.
abstract: To investigate the in vivo handling of human short-chain acyl-CoA dehydrogenase (SCAD) variant proteins, three transgenic mouse lines were produced by pronuclear injection of cDNA encoding the wild-type, hSCAD-wt, and two disease causing folding variants hSCAD-319C>T and hSCAD-625G>A. The transgenic mice were mated with an SCAD-deficient mouse strain (BALB/cByJ) and, in the second generation, three mouse lines were obtained without endogenous SCAD expression but harboring hSCAD-wt, hSCAD-319C>T, and hSCAD-625G>A transgenes, respectively. All three lines had expression of the transgene at the RNA level in liver, muscle or brain tissues. Expression at the protein level was detected only in the brain tissue of hSCAD-wt mice, but here it was significantly higher than the level of endogenous SCAD protein in control mouse brains--in correlation with expression at the RNA level. The results may indicate that the two hSCAD folding variants are degraded by the mouse mitochondrial protein quality control system. Indeed, pulse-chase studies with isolated mitochondria revealed that soluble variant hSCAD protein was rapidly eliminated. This is in agreement with the fact that no disease phenotype developed for any of the lines transgenic for the hSCAD folding variants. The indicated remarkable efficiency of the mouse protein quality control system in the degradation of SCAD folding variants should be further substantiated and investigated, since it might indicate ways to prevent disease-causing effects.
authors.affiliation: Institute of Human Genetics, University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kragh
authors.forename: Christina B
authors.initials: CB
authors.lastname: Pedersen
authors.forename: Stinne P
authors.initials: SP
authors.lastname: Schmidt
authors.forename: Vibeke S
authors.initials: VS
authors.lastname: Winter
authors.forename: Gábor
authors.initials: G
authors.lastname: Vajta
authors.forename: Niels
authors.initials: N
authors.lastname: Gregersen
authors.forename: Lars
authors.initials: L
authors.lastname: Bolund
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Corydon
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D044926:Butyryl-CoA Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D008099:Liver / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000378:metabolism; D009928:Organ Specificity; D012333:RNA, Messenger / Q000096:biosynthesis
chemical_list: D012333:RNA, Messenger; D044926:Butyryl-CoA Dehydrogenase