MAP1A and MAP1B are microtubule-associated proteins which mediate the physical interactions between microtubules and components of the cytoskeleton. MAP1A and MAP1B each consist of a heavy chain subunit and multiple light chain subunits. The protein encoded by this gene is one of the light chain subunits and can associate with either MAP1A or MAP1B. Two transcript variants encoding different isoforms have been found for this gene.The deduced 121-amino acid protein shares 81% identity with rat Map1lc3. Northern blot analysis detected a 1.1-kb transcript in most tissues examined, with highest expression in heart, brain, liver, skeletal muscle, and testis. No MAP1LC3A expression was detected in thymus and peripheral blood leukocytes.