Shank is a novel family of the PSD (post-synaptic density) protein complex. It was found in rat brain and contains multiple sites for protein interaction including a PDZ (PSD-95, Disk-Large, ZO-1) domain that mediates binding to GKAP, ankyrin repeats, a SH3 domain, a SAM domain that mediates multimerization, and a proline-rich domain that binds cortactin. It was reported that these multiple protein-interactions cause shank to function as a scaffold protein in the PSD, cross-linking receptor/PSD-95 complexes and coupling them to regulators of the actin cytoskeleton. A
shn-1 (C33B4.3), C. elegans homologue of shank, was found in the C. elegans genome database and shows about 40% identity over 1,000 amino acids. A
shn-1 shows relatively high sequence identities in the regions of ankyrin repeats and the PDZ domain. GFP expression of promoter regions of
shn-1 was seen mainly in pharyngeal muscle, head sensory neurons, nerve cords and the tail region. Whole-mount immunostaining patterns with shank-1 polyclonal antibodies showed similar expression patterns. shank-1 polyclonal antibodies were raised against ankyrin repeats-containing region of rat shank-1. This expression not only confirms our previous GFP expression results, but also shows the conservation of shank protein. We cloned and sequenced the full cDNA from a cDNA library and a EST clone from Yuji Kohara. Currently we are conducting RNAi experiments to observe loss-of function phenotypes and elucidate its biological role in C.elegans . Screening for deletion mutant by UV-TMP mutagenesis is also under way.