Skip to main content

MAP1B

Domain

Has a highly basic region with many copies of the sequence KKEE and KKEI/V, repeated but not at fixed intervals, which is responsible for the binding of MAP1B to microtubules.

Function

Facilitates tyrosination of alpha-tubulin in neuronal microtubules (By similarity). Phosphorylated MAP1B may play a role in the cytoskeletal changes that accompany neurite extension. Possibly MAP1B binds to at least two tubulin subunits in the polymer, and this bridging of subunits might be involved in nucleating microtubule polymerization and in stabilizing microtubules. Acts as a positive cofactor in DAPK1-mediated autophagic vesicle formation and membrane blebbing.

Involvement in disease

Periventricular nodular heterotopia 9

PVNH9

A form of periventricular nodular heterotopia, a disorder resulting from a defect in the pattern of neuronal migration in which ectopic collections of neurons lie along the lateral ventricles of the brain or just beneath, contiguously or in isolated patches. PVNH9 is an autosomal dominant disorder with incomplete penetrance, characterized by impaired intellectual development, cognitive defects, learning disabilities, and behavior abnormalities. Some patients develop seizures.

None

The disease is caused by variants affecting the gene represented in this entry.

Post-translational modifications

LC1 is generated from MAP1B by proteolytic processing.

S-nitrosylation at Cys-2464 enhances interaction with microtubules, and may act as an effector modification for neuronal nitric oxide synthase control of growth-cone size, growth-cone collapse and axon retraction.

Sequence similarities

Belongs to the MAP1 family.

Cellular localization

  • Cytoplasm
  • Cytoskeleton
  • Cytoplasm
  • Cell junction
  • Synapse
  • Cell projection
  • Dendritic spine
  • Colocalizes with DAPK1 in the microtubules and cortical actin fibers.
  • MAP1 light chain LC1
  • Cytoplasm

Alternative names

  • Microtubule-associated protein 1B
  • MAP-1B
  • MAP1B

Target type

Proteins

Molecular weight

270634Da