PEX11 beta deficiency is lethal and impairs neuronal migration but does not abrogate peroxisome function.
Zellweger syndrome is a lethal neurological disorder characterized by severe defects in peroxisomal protein import. The resulting defects in peroxisome metabolism and the accumulation of peroxisomal substrates are thought to cause the other Zellweger syndrome phenotypes, including neuronal migration defects, hypotonia, a developmental delay, and neonatal lethality. These phenotypes are also manifested in mouse models of Zellweger syndrome generated by disruption of the PEX5 or PEX2 gene. Here we show that mice lacking peroxisomal membrane protein PEX11 beta display several pathologic features shared by these mouse models of Zellweger syndrome, including neuronal migration defects, enhanced neuronal apoptosis, a developmental delay, hypotonia, and neonatal lethality. However, PEX11 beta deficiency differs significantly from Zellweger syndrome and Zellweger syndrome mice in that it is not characterized by a detectable defect in peroxisomal protein import and displays only mild defects in peroxisomal fatty acid beta-oxidation and peroxisomal ether lipid biosynthesis. These results demonstrate that the neurological pathologic features of Zellweger syndrome can occur without peroxisomal enzyme mislocalization and challenge current models of Zellweger syndrome pathogenesis.
Li
Xiaoling
X
Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Baumgart
Eveline
E
Morrell
James C
JC
Jimenez-Sanchez
Gerardo
G
Valle
David
D
Gould
Stephen J
SJ
D000818:Animals; D002465:Cell Movement; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism; D005317:Fetal Growth Retardation / Q000235:genetics; D006801:Humans; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008928:Mitochondria / Q000648:ultrastructure; D009123:Muscle Hypotonia / Q000235:genetics; D009474:Neurons / Q000473:pathology*; D020675:Peroxisomes / Q000378:metabolism*; D021381:Protein Transport; D015211:Zellweger Syndrome / Q000378:metabolism / Q000473:pathology
D005227:Fatty Acids; D008565:Membrane Proteins; C490455:PEX11A protein, human; C490453:PEX11B protein, human; C490452:Pex11b protein, mouse