Involved in microtubule stabilization in many cell types, including neuronal cells (By similarity). Specifically has microtubule cold stabilizing activity (By similarity). Involved in dendrite morphogenesis and maintenance by regulating lysosomal trafficking via its interaction with TMEM106B (PubMed:24357581). Regulates KIF5A-mediated axonal cargo transport (By similarity). Regulates axonal growth during neuron polarization (By similarity). Interacts with calmodulin (via C-terminus); the interaction is dependent on Ca(2+) (By similarity). Interacts with TMEM106B (PubMed:24357581). Interacts with ZDHHC17 (via ANK repeats) (PubMed:26198635). Interacts with ZDHHC13 (via ANK repeats) (PubMed:26198635). Localizes predominantly in the proximal part of the axon (By similarity). Preferentially is concentrated on a portion of the microtubule polymer in which tubulin is modified by detyrosination and acetylation and is also resistant to depolymerization induced by both nocodazole and cold (By similarity). In unpolarized neurons, localizes to the Golgi and to secretory vesicles accumulating transiently at the tips of a subset of neurites (By similarity). Following neuronal polarization and during axon outgrowth, accumulates in the axonal growth cone and subsequently localizes throughout the axon (By similarity). Partially localizes to dendrites in mature neurons (By similarity). Colocalizes with neurofilament (NF)-rich inclusions in spinal cord and brain neurons of patients with amyotrophic lateral sclerosis (ALS) (PubMed:14692697). Expressed in brain (at protein level). Expressed in spinal cord. Isoform 2 expression is up-regulated in the prefrontal cortex (Brodmann's area 46) of patients with schizophrenia (postmortem brain study). Palmitoylated. Probably depalmitoylated by ABHD17A, ABHD17B and ABHD17C. During neuronal polarization, palmitoylation and depalmitoylation cycles regulate MAP6 shuttling between secretory vesicles and microtubules, and its polarized distribution in the axon. Belongs to the STOP family.