Inscuteable Homolog (INSC)

Sequence analysis detected 2 transcripts encoding a 579-amino acid protein and a 532-amino acid protein, which utilize alternative first exons, resulting in the short form lacking the N-terminal 47 amino acids of the long form. The C-terminus of INSC contains 4 putative armadillo repeats and a PDZ-binding motif. Human INSC shows 25% identity with Drosophila Insc, with highest conservation seen in the PDZ-binding motif and the first armadillo repeat. RT-PCR analysis showed expression in human brain, lung, liver, kidney, pancreas, and small intestine, with expression of the short form in lung, pancreas, small intestine, and kidney only.both long and short forms of INSC interacted with cell polarity proteins LGN (GPSM2) and AGS3 (GPSM1) and also with PARD3 and PARD3B.