%0 Journal Article
%T Mapping of the Mouse Actin Capping Protein Beta Subunit Gene
%A Marilyn C Hart
%A Yulia O Korshunova
%A John A Cooper
%J BMC Genomics
%D 2000
%I BioMed Central
%R 10.1186/1471-2164-1-1
%X We isolated genomic clones corresponding to the ¦Â subunit of mouse CP and identified its chromosomal location by interspecies backcross mapping.The CP¦Â gene (Cappb1) mapped to Chromosome 4 between Cdc42 and D4Mit312. Three mouse mutations, snubnose, curly tail, and cribriform degeneration, map in the vicinity of the ¦Â gene.Capping protein (CP) is a ubiquitous actin binding protein that regulates actin assembly and cell motility. CP is a heterodimer composed of ¦Á and ¦Â subunits, each approximately 30 kD. Lower organisms, including Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster, have one gene and one isoform for each of the CP¦Á and ¦Â subunits [1,2,3]. Vertebrates contain three ¦Á subunit isoforms encoded by three different genes and three ¦Â subunit isoforms (¦Â1, ¦Â2, ¦Â3) produced from one gene by alternative splicing [4,5,6].To confirm the genomic complexity of the ¦Â subunit of mouse CP, Southern blots of mouse genomic DNA were cleaved with several restriction enzymes and independently probed with mouse ¦Â1 and ¦Â2 cDNAs. The ¦Â1 and ¦Â2 probes each hybridized to one identical band. To obtain genomic clones that correspond to this pattern, a 129SV genomic library in the lambda FIXII vector (Stratagene) was screened using the complete ¦Â1 cDNA as probe. Positive plaques were purified according to standard procedures [7] and the phage DNA isolated using DEAE-cellulose [8]. Comparison of the hybridization pattern for the genomic clones with the mouse genomic DNA revealed that the patterns were identical, confirming the presence of a single ¦Â gene in the mouse genome.In chicken, the ¦Â1 and ¦Â2 isoforms have been described as the differentially spliced products of a single gene, with the ¦Â1 cDNA containing a 113 bp exon that is absent in the ¦Â2 cDNA [4]. To determine if the murine ¦Â2 isoform is spliced in a manner identical to that of chicken, the sequence of the ¦Â2 cDNA was compared to the corresponding genomic region. Sequence comparison revealed th
%U http://www.biomedcentral.com/1471-2164/1/1