Cloning of cDNA encoding a novel mouse actin-associated protein specifically expressed in lymphoid tissues

A 200 bp novel gene fragment C55 was obtained from a mouse thymic stromal cell subtracted cDNA library by using suppression subtractive hybridization (SSH). GenBank database search and RT-PCR amplification revealed a full-length cDNA of 1 388 bp, which was confirmed by Northern blotting. The full-length cDNA contains an open reading frame of 636 bp, encoding a predicted protein of 212 amino acids, which showed 62%-95% sequence identity with other arthropod and vertebrate SM22alpha. Northern blotting demonstrated differential expression of the mRNA transcript in the two thymic stromal cell lines.