Actinin-associated LIM protein-deficient mice maintain normal development and structure of skeletal muscle.
The actinin-associated LIM protein, ALP, is the prototype of a large family of proteins containing an N-terminal PDZ domain and a C-terminal LIM domain. These PDZ-LIM proteins are components of the muscle cytoskeleton and occur along the Z lines owing to interaction of the PDZ domain with the spectrin-like repeats of alpha-actinin. Because PDZ and LIM domains are typically found in proteins that mediate cellular signaling, PDZ-LIM proteins are suspected to participate in muscle development. Interestingly the ALP gene occurs at 4q35 near the heterochromatic region mutated in facioscapulohumeral muscular dystrophy, indicating a possible role for ALP in this disease. Here, we describe the generation and analysis of mice lacking the ALP gene. Surprisingly, the ALP knockout mice show no gross histological abnormalities and maintain sarcolemmal integrity as determined by serum pyruvate kinase assays. The absence of a dystrophic phenotype in these mice suggests that down-regulation of ALP does not participate in facioscapulohumeral muscular dystrophy. These data suggest that ALP does not participate in muscle development or that an alternative PDZ-LIM protein can compensate for the lack of ALP.
Department of Physiology, University of California at San Francisco, San Francisco, California 94143, USA.
K
K
Jo
B
B
Rutten
R C
RC
Bunn
D S
DS
Bredt
D000818:Animals; D015153:Blotting, Western; D002874:Chromosome Mapping; D003599:Cytoskeleton / Q000378:metabolism; D015536:Down-Regulation; D005822:Genetic Vectors; D005838:Genotype; D006801:Humans; D007150:Immunohistochemistry; D060588:LIM Domain Proteins; D051379:Mice; D018345:Mice, Knockout; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D018482:Muscle, Skeletal / Q000378:metabolism*; D009132:Muscles / Q000196:embryology / Q000502:physiology; D009136:Muscular Dystrophies / Q000235:genetics; D010641:Phenotype; D017434:Protein Structure, Tertiary; D011770:Pyruvate Kinase / Q000097:blood; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction
D060588:LIM Domain Proteins; D008840:Microfilament Proteins; C108834:PDLIM3 protein, human; C484642:Pdlim3 protein, mouse; D011770:Pyruvate Kinase