MAP1B

This gene encodes a protein that belongs to the microtubule-associated protein family. The proteins of this family are thought to be involved in microtubule assembly, which is an essential step in neurogenesis. The product of this gene is a precursor polypeptide that presumably undergoes proteolytic processing to generate the final MAP1B heavy chain and LC1 light chain. Gene knockout studies of the mouse microtubule-associated protein 1B gene suggested an important role in development and function of the nervous system.

Full Name

MICROTUBULE ASSOCIATED PROTEIN 1B

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.

Biological Process

Axon extensionManual Assertion Based On ExperimentTAS:ARUK-UCL
AxonogenesisManual Assertion Based On ExperimentIBA:GO_Central
Cellular response to growth factor stimulusIEA:Ensembl
Cellular response to peptide hormone stimulusIEA:Ensembl
Dendrite developmentManual Assertion Based On ExperimentIBA:GO_Central
Developmental maturationIEA:Ensembl
Establishment of monopolar cell polarityIEA:Ensembl
Induction of synaptic plasticity by chemical substanceIEA:Ensembl
Microtubule bundle formationIEA:Ensembl
Microtubule cytoskeleton organizationManual Assertion Based On ExperimentIBA:GO_Central
Mitochondrion transport along microtubuleIEA:Ensembl
Negative regulation of intracellular transportIEA:Ensembl
Negative regulation of microtubule depolymerizationIEA:Ensembl
Neuron migrationManual Assertion Based On ExperimentTAS:ARUK-UCL
Odontoblast differentiationManual Assertion Based On ExperimentIDA:GO_Central
Peripheral nervous system axon regenerationIEA:Ensembl
Positive regulation of axon extensionIEA:Ensembl
Positive regulation of microtubule polymerizationIEA:Ensembl
Positive regulation of neuron differentiationIEA:Ensembl
Regulation of microtubule depolymerizationManual Assertion Based On ExperimentIBA:GO_Central
Response to carbohydrateIEA:Ensembl
Response to estradiolIEA:Ensembl
Response to inorganic substanceIEA:Ensembl
Response to insecticideIEA:Ensembl
Response to mechanical stimulusIEA:Ensembl
Response to vitamin AIEA:Ensembl
Response to xenobiotic stimulusIEA:Ensembl
Synapse assemblyIEA:Ensembl

Cellular Location

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

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.

PTM

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.