SOLH, A HUMAN HOMOLOG OF THE DROSOPHILA-MELANOGASTER SMALL OPTIC LOBES GENE IS A MEMBER OF THE CALPAIN AND ZINC-FINGER GENE FAMILIES AND MAPS TO HUMAN-CHROMOSOME 16P13.3 NEAR CATM (CATARACT WITH MICROPHTHALMIA)

Mutations in the Drosophila melanogaster smalt optic lobes (sot) gene cause a severe reduction in the neuropiles of the medulla and lobula c omplexes of the adult optic lobes, The predicted protein product of so l contains zinc-finger-like repeats, a calpain-like protease domain, a nd a C-terminal region of unknown function. We have isolated human bra in cDNA for SOLH, a human homologue of sst. The human SOLH gene consis ts of 14 exons distributed over more than 45 kb of genomic DNA. The en coded SOLH protein of 1086 amino acids has strong similarity to the D. melanogaster protein. The calpain-like domain and C-terminal region a re highly conserved (58% identity), and similar Cys(2)-Cys(2) zinc fin gers are present in the N-terminal region. A reported Caenorhabditis e legans homologue contains the calpain domain and C-terminal region, bu t appears to lack the zinc finger region. A single copy of the zinc fi nger sequence is present in adjacent C. elegans genomic cosmid DNA seq uence, and we show that it is part of the C. elegans sol-like transcri pt. Northern analysis of human tissues revealed a SOLH transcript of s imilar to 5 kb that was strongest in human brain, We have mapped the S OLH gene to chromosome 16p13.3 by in situ hybridization, SOLH is a can didate gene for CATM (hereditary cataracts with microphthalmia), which maps in this region. (C) 1998 Academic Press.