| 1988 |
The C-terminal 185 amino acids of MAP2, containing three imperfect 18-amino-acid repeats, constitute the microtubule-binding domain. A subcloned fragment spanning the first two repeats copurified with microtubules through two successive cycles of polymerization/depolymerization, while a control polypeptide from the N-terminal region completely failed to copurify. |
In vitro translation of subcloned fragments followed by microtubule copurification assay |
Science |
High |
3142041
|
| 1988 |
MAP2 is a component of crossbridges between microtubules and neurofilaments in the neuronal cytoskeleton. MAP2 bound isolated neurofilament L protein in vitro, and when tubulin was added and polymerized, neurofilaments were crosslinked with microtubules via MAP2 bridges. |
Quick-freeze deep-etch immunoelectron microscopy with anti-MAP2 antibody decoration, plus in vitro reconstitution with purified neurofilament L protein and tubulin |
The Journal of neuroscience |
High |
3045269
|
| 1988 |
MAP2 mRNA is selectively localized in dendrites of developing neurons, whereas tubulin mRNA is restricted to neuronal cell bodies, establishing a dendritic targeting signal for MAP2 transcript. |
In situ hybridization with specific cDNA probes in developing brain tissue |
Nature |
High |
3200318
|
| 1992 |
Expression of MAP2 is necessary for both neurite extension and cessation of cell division during neuronal differentiation; stable transfectants with MAP2 antisense RNA showed reduced MAP2 protein, failed normal morphological differentiation, and failed to withdraw from the cell cycle. |
Stable antisense RNA transfection in embryonal carcinoma cells with retinoic acid-induced differentiation |
Cell |
High |
1997209
|
| 1992 |
Transfection of MAP2c or tau cDNA into fibroblasts stabilizes microtubules against depolymerizing reagents and enriches microtubules in acetylated alpha-tubulin, demonstrating that these MAPs induce post-translational modification of tubulin. |
cDNA transfection into fibroblasts, drug-resistance assay, immunofluorescence with anti-acetylated tubulin antibody |
Journal of cell science |
High |
1487506
|
| 2002 |
MAP2 anchors the regulatory subunit II of cAMP-dependent protein kinase (PKA) in dendrites. MAP2-deficient mice show reduced microtubule density and dendritic length, significant reduction of PKA subunits in dendrites and total PKA, and markedly reduced phosphorylated CREB induction after forskolin stimulation. |
MAP2 knockout mouse analysis: immunofluorescence, Western blot for PKA subunits, pCREB induction assay in cultured neurons |
The Journal of cell biology |
High |
12163474
|
| 1989 |
High-molecular-weight MAP2 and low-molecular-weight MAP2c are generated by alternative splicing from a single gene and share the C-terminal tubulin-binding domain and a short N-terminal sequence. MAP2c lacks 1,342 amino acids of the filamentous sidearm domain present in high-MW MAP2, and MAP2c mRNA is not present in dendrites, indicating the dendritic targeting signal is specific to the high-MW isoform. |
cDNA cloning, sequence comparison, in situ hybridization for mRNA localization |
Nature |
High |
2770869
|
| 1995 |
MAP2 is prevented from entering the axon by its N-terminal projection domain. Microtubule binding of MAP2/MAP2C is tighter in the cell body and dendrites than in the axon, a property determined by the microtubule-binding domain and suggested to be regulated by phosphorylation. |
Transfection of tagged tau, MAP2, MAP2C, and chimeric/deletion mutants into primary cultured neurons |
Neuron |
High |
7857650
|
| 1990 |
NMDA receptor activation induces rapid (~70%) dephosphorylation of MAP2 in hippocampal slices, blocked by competitive and noncompetitive NMDA antagonists but not non-NMDA receptor antagonists, suggesting NMDA-stimulated protein phosphatase (possibly calcineurin) dephosphorylates MAP2. |
32P-orthophosphate labeling of hippocampal slices, pharmacological dissection with receptor antagonists |
Neuron |
High |
2169265
|
| 1996 |
Glutamate produces bidirectional regulation of MAP2 phosphorylation in neurons: a rapid transient increase via metabotropic receptors (attenuated by CaMK and PKC inhibitors) followed by persistent dephosphorylation via NMDA receptor activation of calcineurin (PP2B). The phosphorylation state of MAP2 determines its interaction with microtubules and actin. |
32P metabolic labeling of neurons, pharmacological dissection with receptor antagonists and kinase/phosphatase inhibitors |
Neuron |
High |
8789950
|
| 1999 |
MAP2B (a well-established AKAP) directly binds the alpha1 subunit of class C L-type Ca2+ channels in neurons; this association is independent of microtubules. PKA is an integral part of the immunoisolated class C channel complex, and MAP2B mediates recruitment of PKA to postsynaptic sites. |
Co-immunoprecipitation from rat brain extracts, protein overlay binding assay with 32P-labeled RIIβ, immunoblotting, in vitro direct binding assay |
The Journal of biological chemistry |
High |
10514522
|
| 1999 |
MARK kinases phosphorylate MAP2c on its microtubule-binding domain in transfected CHO cells, leading to detachment of MAP2c from microtubules and increased microtubule dynamic instability; prolonged MARK2 expression causes microtubule disruption and cell death. |
Inducible expression of MARK1/MARK2 in transfected CHO cells, immunofluorescence, cell viability assay |
Cell motility and the cytoskeleton |
Medium |
10542369
|
| 2000 |
GSK3β phosphorylates MAP2C in co-transfected COS-1 cells, and this phosphorylation prevents microtubule bundle formation. Phosphorylated MAP2C species are enriched in cytoskeleton-unbound fractions, indicating that GSK3β-mediated phosphorylation reduces MAP2 binding to microtubules. |
Co-transfection of MAP2C and GSK3β (wild-type or mutant) in COS-1 cells, immunofluorescence for microtubule bundles, cytoskeletal fractionation, lithium chloride rescue |
European journal of cell biology |
Medium |
10826493
|
| 2000 |
PKA activity disrupts the MAP2-microtubule interaction in living HeLa cells and promotes MAP2c localization to peripheral actin-rich membrane ruffles. PKA phosphorylates serines within KXGS motifs in each tubulin-binding repeat; single-site glutamic acid substitution was sufficient to disrupt microtubule binding, and double/triple mutations promoted MAP2c-actin colocalization. |
Live-cell imaging, detergent extraction assay, site-directed mutagenesis (Glu substitutions), immunofluorescence colocalization in HeLa cells |
Molecular biology of the cell |
High |
11029056
|
| 2000 |
All three neuronal MAP2 isoforms bind specifically to the SH3 domains of c-Src and Grb2 via the microtubule-binding domain (not a PXXP motif). Endogenous MAP2-Src and MAP2-Grb2 interactions were confirmed by co-immunoprecipitation from brain lysate. ERK2 phosphorylation of MAP2c inhibits the MAP2-SH3 interaction. |
GST-SH3 pulldown assay, co-immunoprecipitation from brain lysate, in vitro kinase assay with ERK2 |
The Journal of biological chemistry |
High |
10781592
|
| 2001 |
MAP2c binds Fyn kinase through the RTPPKSP SH3-binding motif. Fyn phosphorylates MAP2c on tyrosine. ERK2-mediated threonine phosphorylation of the RTPPKSP motif abolishes the MAP2c-Fyn interaction. Co-immunoprecipitation of Fyn and MAP2c from human fetal brain confirmed the in vivo interaction. |
GST-SH3 pulldown, co-immunoprecipitation from human fetal brain homogenate, ELISA binding assay, co-transfection in COS7 cells with kinase assay |
The Journal of biological chemistry |
High |
11546790
|
| 1997 |
cdc2 kinase phosphorylation of MAP2 (>60% of phosphates in the microtubule-binding region) abolishes both microtubule-stabilizing and microtubule-nucleating activities. PKA phosphorylation (~70% in the projection region) reduces only microtubule-nucleating activity, not stabilization. These distinct effects were demonstrated by direct observation of individual microtubules. |
In vitro phosphorylation by purified PKA or cdc2 kinase, dark-field microscopy observation of individual microtubules, spontaneous polymerization assay |
Biochemistry |
High |
9376363
|
| 2003 |
Rho-kinase phosphorylates MAP2 at Ser1796, and myosin phosphatase (MBS subunit) binds MAP2 and can dephosphorylate it. These were identified as novel substrates of the Rho-kinase/myosin phosphatase pathway. |
In vitro kinase assay, phosphorylation site mapping by mass spectrometry/sequencing, interaction assay with MBS subunit |
Journal of neurochemistry |
Medium |
14535960
|
| 2000 |
PP2A, but not PP2B, regulates MAP2 phosphorylation at multiple sites in rat brain slices; inhibition of PP2A with okadaic acid induced phosphorylation of MAP2 and impaired its microtubule-binding activity, establishing PP2A as the major phosphatase regulating MAP2. |
Metabolically competent rat brain slices treated with okadaic acid (PP2A inhibitor) or cyclosporin A (PP2B inhibitor), Western blot with phospho-specific antibodies, microtubule-binding assay |
Brain research |
Medium |
10640627
|
| 2012 |
PP2A/Bα directly binds MAP2 and dephosphorylates it. The binding site is within the microtubule-binding domain and upstream proline-rich region of MAP2c, overlapping with the RTPPKSP motif also recognized by Fyn kinase. Fyn inhibits the PP2A/Bα-MAP2 interaction; tau and MAP2 compete for binding to PP2A/Bα. |
Co-purification from bovine brain, co-immunoprecipitation, in vitro binding assay with peptides, competition assay, immunofluorescence colocalization |
The Journal of biological chemistry |
High |
22403409
|
| 1990 |
The MAP2-binding and P75-binding domain in the PKA regulatory subunit RIIβ is located within its N-terminal 50 amino acids. Fusion proteins containing RIIβ amino acids 1–50 bound MAP2 and P75 immobilized on nitrocellulose; deletion of residues 1–25 or 25–96 abolished binding. |
Expression of truncated RIIβ-fusion proteins in E. coli, overlay binding assay on nitrocellulose filters |
The Journal of biological chemistry |
Medium |
2254332
|
| 2006 |
MAP2 functions as a receptor for the neurosteroid pregnenolone (PREG) and its analog MePREG. PREG and MePREG bind MAP2 and stimulate microtubule polymerization. RNA interference knockdown of MAP2 prevents the stimulatory effects of PREG/MePREG on neurite extension but does not affect progesterone action. |
Binding assay, microtubule polymerization assay, RNA interference knockdown in PC12 cells, neurite outgrowth measurement |
Proceedings of the National Academy of Sciences |
Medium |
16537405
|
| 1993 |
MAP2c-transfected non-neuronal cells form microtubule-containing processes specifically upon actin depolymerization with cytochalasin B. This effect is specific to MAP2c (not taxol-stabilized microtubules), suggesting MAP2c confers stability, bundling, and stiffness on microtubules enabling process outgrowth against cortical actin tension. |
cDNA transfection into non-neuronal cells, cytochalasin B treatment, video time-lapse microscopy |
Development |
Medium |
8392463
|
| 1993 |
MAP2C-bundled microtubules in transfected fibroblasts are extremely stable (less than 10% tubulin exchange within 1 hour) but still incorporate exogenously introduced tubulin rapidly at distal ends, demonstrating that MAP2C stabilizes microtubule bundles while preserving plus-end assembly. |
Microinjection of biotin-labeled tubulin, photoactivation of caged fluorescein-labeled tubulin, immunofluorescence |
The Journal of cell biology |
High |
8421058
|
| 1992 |
MAP2c expression in non-neuronal cells induces MTOC-independent microtubule polymerization and bundling. At higher expression levels, increasing proportions of microtubules form independently of the MTOC; MAP2c imparts both stability and stiffness to microtubules. |
cDNA transfection in non-neuronal cell lines, immunofluorescence, comparison with taxol and DMSO stabilization |
Development |
Medium |
1338311
|
| 1994 |
MAP2 (but not MAP2C or tau) binds phosphatidylinositol vesicles with high affinity (Kd ~51 nM), approximately 30-fold higher than MAP2C (~1.4 µM). This high affinity requires two sites: a low-affinity site in the C-terminal domain (shared with MAP2C/tau) and a high-affinity site (~221 nM) within the MAP2-specific projection domain (absent from MAP2C due to alternative splicing). |
Vesicle binding assay with purified proteins, thrombin digestion of MAP2C to map binding domains |
Biochemistry |
Medium |
8025110
|
| 1994 |
MAP2 binds to both microtubules/tubulin dimers and microfilaments/G-actin in a concentration-dependent manner. Microtubule-bound MAP2 shows diminished ability to bind microfilaments/G-actin, while microfilament-bound MAP2 efficiently binds microtubules and tubulin, suggesting an asymmetric cross-linking interaction. |
Solid-phase immunoassay on 96-well microtiter plates with purified proteins |
Biochemistry |
Medium |
8038171
|
| 2005 |
Soluble amyloid-β oligomers induce proteolysis of MAP2a, MAP2b, and MAP2c through calpain activation (triggered by Ca2+ dysregulation and ROS), which on its own is sufficient to cleave all MAP2 isoforms. Antioxidants prevent MAP2 proteolysis, linking ROS to calpain-mediated MAP2 degradation. |
In vitro Aβ treatment of neurons, calpain inhibitor experiments, caspase-3 inhibitor experiments, Western blot |
The Journal of biological chemistry |
Medium |
16234245
|
| 1994 |
MAP2 phosphorylation at Ser136, a Ser-Pro motif, occurs in vivo and in vitro specifically by proline-directed kinases (MAP kinase, GSK-3, cdk family members) but not by PKA, PKC, or CaMKII. After microinjection into cell lines, dephosphorylated MAP2 becomes phosphorylated at Ser136; microtubule reorganization by injected MAP2 is independent of Ser136 phosphorylation. |
In vitro kinase assays, site-directed mutagenesis of Ser136, monoclonal antibody epitope mapping, microinjection into cell lines |
European journal of cell biology |
High |
7525290
|
| 1983 |
MAP2 is present in dendritic spines and colocalizes with actin at the filamentous compartment of spines, endomembranes of the spine apparatus, smooth endoplasmic reticulum, and postsynaptic density, indicating MAP2 is an actin-associated protein in dendritic spines. |
Immunogold electron microscopy with double-labeling using anti-MAP2 and anti-actin antibodies |
Proceedings of the National Academy of Sciences |
Medium |
6572937
|
| 1995 |
A MAP2-associated kinase (embryonic MAP2 kinase, Mr=100,000) co-purified with chicken embryonic MAP2 phosphorylates MAP2 at serine residues and releases MAP2 from microtubules, restoring kinesin- and dynein-driven microtubule motility that is otherwise inhibited by MAP2. This kinase is cAMP-independent and distinct from cdc2 kinase, MAPK, and NIMA kinase in its ability to alter MAP2-microtubule affinity. |
In vitro motility assay, kinase co-purification, in vitro phosphorylation with multiple kinase comparisons |
The Journal of biological chemistry |
Medium |
7759496
|
| 2003 |
MAP2 physically associates with the NMDA receptor complex in hippocampal neurons, demonstrated by co-immunoprecipitation. NMDA receptor activation is a prominent trigger for MAP2 breakdown; calcium influx through the NMDA receptor channel and calcium release from mitochondria trigger MAP2 degradation limited by calpain activity. |
Co-immunoprecipitation from hippocampal slice lysates, pharmacological dissection with NMDA receptor antagonists, calpain inhibitors, calcium chelators |
Brain research |
Medium |
12834896
|
| 2011 |
MAP2 mRNA localizes to dendrites in distinct RNPs containing very few RNA molecules (low copy number). The number of MAP2 molecules per RNP particle is affected by synaptic activity and Staufen 2, indicating that RNP composition is dynamically regulated. |
Single-molecule fluorescence in situ hybridization (smFISH), live-cell imaging, Staufen 2 knockdown, synaptic activity manipulation |
EMBO reports |
Medium |
21869818
|
| 2012 |
L1CAM (L1) directly binds MAP2c (but not MAP2a/b) through its intracellular domain, as shown by ELISA. L1 upregulates MAP2a/b/c expression in hippocampal neurons via the MAPK pathway. Deficiency in both L1 and MAP2 reduces neurite outgrowth in vitro. |
ELISA binding assay, co-immunoprecipitation, Western blot from L1-deficient transgenic mice, MAPK pathway inhibition, neurite outgrowth assay |
Molecular and cellular neurosciences |
Medium |
22503709
|
| 2021 |
Hyperphosphorylation of MAP2 at Ser1782 (pS1782) in schizophrenia reduces MAP2 binding to microtubules, as confirmed by computational modeling and experimental validation. A phosphomimetic S1782E transgenic mouse shows reduced basilar dendritic length, complexity, and spine density. Overexpression of wild-type and phosphomimetic MAP2 reduces protein synthesis in vitro, and the MAP2 interactome is enriched for proteins involved in protein translation. |
Unbiased phosphoproteomics, computational modeling, phosphomimetic transgenic mouse (S1782E), co-immunoprecipitation/mass spectrometry for interactome, protein synthesis assay |
Molecular psychiatry |
High |
33526823
|
| 1996 |
Juvenile MAP2c and mature MAP2 induce distinct microtubule spacing and process morphologies when expressed in Sf9 cells. MAP2c induces multiple short thin processes with variable, close microtubule spacing; mature MAP2 induces fewer, thicker processes with a proximo-distal taper in microtubule number and wider spacing, demonstrating that MAP2 isoforms serve as architectural elements establishing specific microtubule arrangements. |
Baculovirus-mediated expression in Sf9 cells, electron microscopy of process cross-sections |
Molecular biology of the cell |
Medium |
8868472
|
| 1996 |
Transgenic MAP2c protein in adult mouse neurons is sorted to dendrites but not axons despite its mRNA being restricted to cell bodies, demonstrating that dendritic targeting of MAP2c depends on a signal in the protein itself, not on mRNA transport. |
Transgenic mouse overexpression of MAP2c, in situ hybridization for mRNA localization, immunofluorescence for protein localization |
The Journal of neuroscience |
High |
8627364
|
| 1983 |
MAP2 binds to the Sau96.1 restriction fragment of mouse satellite DNA containing poly(dA/dT) sequences; DNase protection assay showed MAP2 protects poly(dA)4/poly(dT)4 sequences from digestion. |
DNA-binding assay, DNase protection experiment with MAP2-DNA complex |
The EMBO journal |
Low |
10872313
|
| 2020 |
NCAM2 forms a protein complex with MAP2 and 14-3-3γ/ζ in neurons; NCAM2 depletion results in destabilization of the microtubular network and reduced MAP2 signal, establishing MAP2 as part of an NCAM2-dependent cytoskeletal regulatory complex for dendritic architecture. |
Co-immunoprecipitation, proteomic analysis, knockdown in hippocampal neurons with morphological readout, in vivo cortical migration assay |
Cerebral cortex |
Medium |
32043120
|