Conservation of a short sequence motif within transmembrane segment S3.

<p>Sequence comparison within the S3 region of selected voltage-gated as well as voltage-independent cation channels, including TRPM8 and TRPM2. The amino acid sequences are shown in single letter code. The highly conserved N-x-x-D motif is highlighted with the outer pair of amino acid residues labeled in red and the inner pair in orange. Further highly conserved amino acid residues upstream of the N-x-x-D-motif are given in bold letters. The glycine residue at position 805 in the sequence of human TRPM8 which is crucial for the icilin sensitivity of the channel is marked in blue. Accession numbers are as follows human TRPM8: Q7Z2W7; human TRPM2: O94759; human TRPA1: O75762; human TRPC3: Q13507, Shaker H4 (KCNAS_DROME): P08510; human sodium channel type 2 alpha subunit (SCN2A), domain 4: Q99250; voltage-gated sodium channel from Bacillus halodurans (NaChBac): Q9KCR8; human L-type calcium channel subunit alpha 1C (CACNA1C) domain 4: Q13936.