Interaction of HPC-1/syntaxin 1A with the cytoskeletal protein, tubulin.

It is believed that HPC-1/syntaxin 1A regulates the intracellular membrane transport. We found a possible tubulin binding motif like sequence in residues 89 approximately 106 of HPC-1/syntaxin 1A. To determine whether or not HPC-1/syntaxin 1A binds to tubulin, we performed in vitro binding studies. We showed that both the rat brain and recombinant HPC-1/syntaxin 1A bound to tubulin in vitro. Competition experiments with synthetic peptides revealed that HPC-1/syntaxin 1A bound to tubulin at residues 89 approximately 106 which were supposed to constitute the tubulin binding consensus sequence.