Disease relevance of Mtap1a

• Through a transgenic rescue experiment, we verified that sequence polymorphisms in the neuron-specific microtubule-associated protein 1a gene (Mtap1a) observed in the susceptible strain C57BL/6J (B6) are crucial for the hearing-loss phenotype [1].
• Interestingly, the same chromosome 2 region identified for the hearing modifier of tubby, the moth1 locus, showed a peak lod score of 2.3 for protection from retinal degeneration [2].
• Monoclonal antibodies [SRIF, protein kinase C (rod bipolar cells marker), microtubule associated protein 1A (ganglion cell marker)] and polyclonal antibodies (anti-sst(1), sst(2A), sst(4) receptor) were applied to 10-14mum sections of retinas fixed in paraformaldehyde [3].

High impact information on Mtap1a

• The axoplasmic transport of MAP 1A differed from that of tubulin [4].
• In this study we identified MAP 1A in mouse retinal ganglion cells and characterized for the first time its in vivo dynamics in relation to axonally transported tubulin [4].
• Glial cells of the optic nerve synthesized considerably less MAP 1A than neurons [4].
• Synthesis, axonal transport, and turnover of the high molecular weight microtubule-associated protein MAP 1A in mouse retinal ganglion cells: tubulin and MAP 1A display distinct transport kinetics [4].
• In brain microtubule protein, MAP-1B appears to be phosphorylated in vitro by an endogenous casein kinase II-like activity which also phosphorylates the related protein MAP-1A but scarcely phosphorylates MAP-2 [5].

Biological context of Mtap1a

• A major QTL, designated asmodifieroftubbyhearing1 ( moth1 ), was identified on chromosome 2 with a LOD score of 33.4 ( P < 10(-33)) in the AKR intercross (181 mice) and of 6.0 ( P < 10(-6)) in the CAST intercross (46 mice) [6].
• Microtubule-associated protein 1A is the fibroblast HMW MAP undergoing mitogen-stimulated serine phosphorylation [7].

Anatomical context of Mtap1a

• Microtubule-associated protein 1A (MAP1A) is a high-molecular-weight protein that is comprised of a heavy chain and a light chain (LC2) and is widely distributed along the microtubules in both mature neurons and glial cells [8].
• Antibody A stained MAP1A in pyramidal and stellate cells, including dendrites that crossed layer IV in the septa between barrels [9].

Associations of Mtap1a with chemical compounds

• Data collected from yeast two-hybrid assays of various MAP1A domains confirmed that the interaction of LC2 and NH2-terminal of MAP1A heavy chain is important for microtubule binding [8].
• Here, we identified, by double-immunofluorescent labeling, MAP1A isoform and serotonin 5-HT(2A) receptor distribution [9].

Other interactions of Mtap1a

• Genetic modification of hearing in tubby mice: evidence for the existence of a major gene (moth1) which protects tubby mice from hearing loss [6].
• Immunoblotting of the pituitary MAP fraction revealed the presence of appreciable quantities of MAP 1A, MAP 1B, and MAP 2 polypeptides [10].

Analytical, diagnostic and therapeutic context of Mtap1a

• Immunoblotting indicated once again that MAP 1A, MAP 1B, and MAP 2 were included among the MAPs [10].

References