Lig4^tiny

This mutation, identified in an ENU mutagenesis screen for immunologic mutants, has been identified as an A-to-G transition in exon 2, at nucleotide position 1161 of the cDNA sequence (transcript Lig4-201; ENSMUST00000095476). This results in replacement of tyrosine by cysteine at amino acid position 288 (Y288C) of the protein, which resides in the catalytic domain. Western blot and immunofluorescent analysis of extracts from homozygous mutant mouse embryonic fibroblasts (MEFs) reveal 5-fold reduction in the protein level. Although the mutant protein complexes stably with XRCC4, in vivo adenylation activity is reduced 10-fold in mutant versus wild-type MEFs. (J:122725)