Microtubule-associated protein 2 is a protein in humans that is encoded by the MAP2 gene. [5] [6]
This gene encodes a protein that belongs to the microtubule-associated protein family. The proteins of this family were originally isolated since they copurify with tubulin in polymerization experiments: tubulin in cell extracts can be made to polymerize to produce microtubules (MT) under the influence of heat and the addition of GTP, and the MT can then be collected by centrifugation. When this is done a series of microtubule associated proteins are collected along with the MT and can be detected by SDS-PAGE and other methods. Brain extracts are rich in several of these proteins, MAP2 being one of these. The single MAP2 gene produces four major transcripts producing four proteins, MAP2A, MAP2B, MAP2C and MAP2D. MAP2A and MAP2B are very high molecular weight proteins, with apparent molecular weight on SDS-PAGE about 250 kDa, while MAP2C and MAP2D are much lower molecular weight forms with apparent SDS-PAGE size about 70 kDa. [7] All forms of MAP2 share a common core sequence which includes MT binding domains, 18 amino acid sequences which are found in other MT associated proteins such as MAP Tau and MAP1B. The MAP2 isoforms are thought to be involved in MT assembly, which is an essential step in neuritogenesis. MAP2 serves to stabilize MT growth by crosslinking MT with intermediate filaments and other MTs. MAP2 isoforms are neuron-specific cytoskeletal proteins enriched in dendrites and perikarya, implicating a role in determining and stabilizing neuronal morphology during neuron development. As a result antibodies to MAP2 are widely used to identify neuronal cells and trace dendritic processes in experimental contexts.
MAP2 has been shown to interact with Grb2, [8] [9] NEFL [10] and MYO7A. [11] All MAP2 isoforms bind to microtubules.
The tau proteins form a group of six highly soluble protein isoforms produced by alternative splicing from the gene MAPT. They have roles primarily in maintaining the stability of microtubules in axons and are abundant in the neurons of the central nervous system (CNS), where the cerebral cortex has the highest abundance. They are less common elsewhere but are also expressed at very low levels in CNS astrocytes and oligodendrocytes.
In cell biology, microtubule-associated proteins (MAPs) are proteins that interact with the microtubules of the cellular cytoskeleton. MAPs are integral to the stability of the cell and its internal structures and the transport of components within the cell.
Hippocalcin is a protein that in humans is encoded by the HPCA gene.
Protein kinase C, zeta (PKCζ), also known as PRKCZ, is a protein in humans that is encoded by the PRKCZ gene. The PRKCZ gene encodes at least two alternative transcripts, the full-length PKCζ and an N-terminal truncated form PKMζ. PKMζ is thought to be responsible for maintaining long-term memories in the brain. The importance of PKCζ in the creation and maintenance of long-term potentiation was first described by Todd Sacktor and his colleagues at the SUNY Downstate Medical Center in 1993.
Microtubule-associated protein 4 is a protein that in humans is encoded by the MAP4 gene.
Disks large homolog 2 (DLG2) also known as channel-associated protein of synapse-110 (chapsyn-110) or postsynaptic density protein 93 (PSD-93) is a protein that in humans is encoded by the DLG2 gene.
Tubulin beta-2A chain is a protein that in humans is encoded by the TUBB2A gene.
Tubulin alpha-4A chain is a protein that in humans is encoded by the TUBA4A gene.
Dynamin-1 is a protein that in humans is encoded by the DNM1 gene.
Alpha II-spectrin, also known as Spectrin alpha chain, brain is a protein that in humans is encoded by the SPTAN1 gene. Alpha II-spectrin is expressed in a variety of tissues, and is highly expressed in cardiac muscle at Z-disc structures, costameres and at the sarcolemma membrane. Mutations in alpha II-spectrin have been associated with early infantile epileptic encephalopathy-5, and alpha II-spectrin may be a valuable biomarker for Guillain–Barré syndrome and infantile congenital heart disease.
Tubulin alpha-1B chain is a protein that in humans is encoded by the TUBA1B gene.
Serine/threonine-protein kinase MARK2 is an enzyme that in humans is encoded by the MARK2 gene.
Acid-sensing ion channel 1 (ASIC1) also known as amiloride-sensitive cation channel 2, neuronal (ACCN2) or brain sodium channel 2 (BNaC2) is a protein that in humans is encoded by the ASIC1 gene. The ASIC1 gene is one of the five paralogous genes that encode proteins that form trimeric acid-sensing ion channels (ASICs) in mammals. The cDNA of this gene was first cloned in 1996. The ASIC genes have splicing variants that encode different proteins that are called isoforms.
Serine/threonine-protein kinase MARK1 is an enzyme that in humans is encoded by the MARK1 gene.
Phosphorylase b kinase gamma catalytic chain, skeletal muscle isoform is an enzyme that in humans is encoded by the PHKG1 gene.
Microtubule-associated proteins 1A/1B light chain 3A is a protein that in humans is encoded by the MAP1LC3A gene. Two transcript variants encoding different isoforms have been found for this gene.
MAP/microtubule affinity-regulating kinase 3 is an enzyme that in humans is encoded by the MARK3 gene.
Tubulin beta chain is a protein that in humans is encoded by the TUBB gene.
2′,3′-Cyclic-nucleotide 3'-phosphodiesterase is an enzyme that in humans is encoded by the CNP gene.
Neurotubules are microtubules found in neurons in nervous tissues. Along with neurofilaments and microfilaments, they form the cytoskeleton of neurons. Neurotubules are undivided hollow cylinders that are made up of tubulin protein polymers and arrays parallel to the plasma membrane in neurons. Neurotubules have an outer diameter of about 23 nm and an inner diameter, also known as the central core, of about 12 nm. The wall of the neurotubules is about 5 nm in width. There is a non-opaque clear zone surrounding the neurotubule and it is about 40 nm in diameter. Like microtubules, neurotubules are greatly dynamic and the length of them can be adjusted by polymerization and depolymerization of tubulin.