MAP1B 1–126 interacts with tubulin isoforms and induces neurite outgrowth and neuronal death of cultured cortical neurons

Previously we reported that overexpression of MAP1B containing N-terminal 126 amino acids promoted neuronal death. Here, we identified α-, β-, and βIII-tubulins as proteins interacting with MAP1B 1–126 by two-hybrid and pull-down assays. Transfection experiments indicated that MAP1B 1–126 interacts with microtubules, but to a much lesser extent than two previously reported microtubule-binding domains. Overexpression of MAP1B 1–126 induced both neurite extension and neuronal death, suggesting that MAP1B 1–126 could be involved in neuronal degeneration and aberrant sprouting.

► The N-terminal 126 amino acids of MAP1B was found to interact with tubulins.
► The interaction was relatively weak.
► Like the KKEE(I/V) repeated region, MAP1B 1–126 induced neurite extension.
► MAP1B 1–126 also induced caspase-dependent neuronal death.