Microtubule-associated protein 2 (MAP2) is a microtubule-associated protein involved in microtubule assembly and stability. It binds to the SH3 domains of c-Src and Grb2, and may serve as a molecular scaffold upon which cytoskeleton-modifying proteins assemble and dissociate in response to neuronal activity []. In humans MAP2 has several isoforms resulting from alternative splicing of a single gene. One of the isoform, MAP-2c, can directly recruit multiple signaling proteins important for central nervous system development [].
Kinase noncatalytic C-lobe domain containing 1 (KNDC1), also known as very-KIND, is a brain-specific Ras guanine nucleotide exchange factor (RasGEF) that regulates microtubule-associated protein 2 (MAP2) during dendrite morphogenesis [, ]. It contains two kinase noncatalytic C-lobe domains (KIND1 and KIND2), a RasGEF N-terminal domain (RasN) and a putative RasGEF domain []. The KIND2 domain regulates dendrite complexity via targeting of v-KIND to MAP2 associated with the dendritic microtubule cytoskeleton [].
Microtubule-associated protein 4 (MAP4) is a non-neuronal microtubule-associated protein that promotes microtubule assembly [, ]. It contains a microtubule binding domain (Tau/MAP repeats) that shares homology with neuronal microtubule-associated protein MAP2 and Tau []. It is a ubiquitous heat-stable MAP responsible for stabilisation of microtubules []. Overexpression of MAP4 causes a shift of tubulin dimers to a polymerised fraction and formed dense, stable microtubule networks []. The persistent transcriptional up-regulation of MAP4, cardiac alpha- and beta-tubulinis is linked to the cytoskeletal abnormality during severe pressure overload-induced cardiac hypertrophy [].
