Phosphorylation-dependent Localization of Microtubule-associated Protein MAP2c to the Actin Cytoskeleton

Ozer, Rachel S.; Halpain, Shelley

doi:10.1091/mbc.11.10.3573

Cited by 109 publications

(105 citation statements)

References 48 publications

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“…Microtubule binding of MAP2c is repressed by phosphorylation and MAP2c is found to be associated with the actin cytoskeleton after phosphorylation (32). The fact that MAP2c is released from microtubules by phosphorylation (32) correlates well with the recent finding that binding of Dcx to microtubules is negatively regulated by phosphorylation of serine residues 47 and 297, a reaction mediated by protein kinase A, MAP/microtubule affinity regulatory kinase, and Cdk5 (13,14).…”

Section: Discussionsupporting

confidence: 53%

Doublecortin Association with Actin Filaments Is Regulated by Neurabin II

Tsukada

Prokscha

Ungewickell

et al. 2005

Journal of Biological Chemistry

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Mutations in the human Doublecortin (DCX) gene cause X-linked lissencephaly, a neuronal migration disorder affecting the neocortex and characterized by mental retardation and epilepsy. Because dynamic cellular asymmetries such as those seen in cell migration critically depend on a cooperation between the microtubule and actin cytoskeletal filament systems, we investigated whether Dcx, a microtubule-associated protein, is engaged in cytoskeletal cross-talk. We now demonstrate that Dcx co-sediments with actin filaments (F-actin), and using light and electron microscopy and spin down assays, we show that Dcx induces bundling and crosslinking of microtubules and F-actin in vitro. It has recently been shown that binding of Dcx to microtubules is negatively regulated by phosphorylation of the Dcx at Ser-47 or Ser-297. Although the phosphomimetic green fluorescent protein (GFP)-Dcx S47E transfected into COS-7 cells had a reduced affinity for microtubules, we found that pseudophosphorylation was not sufficient to cause Dcx to bind to F-actin. When cells were co-transfected with neurabin II, a protein that binds F-actin as well as Dcx, GFP-Dcx and to an even greater extent GFP-Dcx S47E became predominantly associated with filamentous actin. Thus Dcx phosphorylation and neurabin II combinatorially enhance Dcx binding to F-actin. Our findings raise the possibility that Dcx acts as a molecular link between microtubule and actin cytoskeletal filaments that is regulated by phosphorylation and neurabin II.

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Section: Discussionsupporting

confidence: 53%

Doublecortin Association with Actin Filaments Is Regulated by Neurabin II

Tsukada

Prokscha

Ungewickell

et al. 2005

Journal of Biological Chemistry

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“…Because the sensitivity of the 5D CACONCACO spectra was not sufficient to assign minor phosphorylation sites, we designed several mutants (S184D, S189D/S435D, S199D/ S435D, T220E, S319D/S435D, T320E/S435D, S342D/S435D, S350D/S435D, S367D/S435D, S382D/S435D, and S435D) based on our MS data and on phosphorylation sites reported in the literature (28). The mutants were uniformly 15 N-labeled and phosphorylated, and the 1 H, 15 N HSQC spectra were recorded.…”

Section: Verification Of Nmr Assignment Of Phosphorylated Residues Bymentioning

confidence: 99%

“…Moreover, binding to microtubules is in equilibrium with the interactions of MAPs with other components of the cytoskeleton. Phosphorylation in MTBRs promotes MAP2c localization to actin-rich regions of neurons (28), with a direct impact on neuronal development and plasticity (19,61,62). It is evident that the kinetics of phosphorylation is an important factor in determining the balance of the aforementioned effects and contributes to the specificity of the control of microtubule stability by Tau and MAP2c under different physiological conditions and in different regions of neurons (8).…”

Section: Phosphorylation Of Map2c and Interaction With 14-3-3mentioning

confidence: 99%

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Quantitative mapping of microtubule-associated protein 2c (MAP2c) phosphorylation and regulatory protein 14-3-3ζ-binding sites reveals key differences between MAP2c and its homolog Tau

Jansen

Melková

Trošanová

et al. 2017

Journal of Biological Chemistry

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Edited by Norma AllewellMicrotubule-associated protein 2c (MAP2c) is involved in neuronal development and is less characterized than its homolog Tau, which has various roles in neurodegeneration. Using NMR methods providing single-residue resolution and quantitative comparison, we investigated molecular interactions important for the regulatory roles of MAP2c in microtubule dynamics. We found that MAP2c and Tau significantly differ in the position and kinetics of sites that are phosphorylated by cAMP-dependent protein kinase (PKA), even in highly homologous regions. We determined the binding sites of unphosphorylated and phosphorylated MAP2c responsible for interactions with the regulatory protein 14-3-3 . Differences in phosphorylation and in charge distribution between MAP2c and Tau suggested that both MAP2c and Tau respond to the same signal (phosphorylation by PKA) but have different downstream effects, indicating a signaling branch point for controlling microtubule stability. Although the interactions of phosphorylated Tau with 14-3-3 are supposed to be a major factor in microtubule destabilization, the binding of 14-3-3 to MAP2c enhanced by PKA-mediated phosphorylation is likely to influence microtubule-MAP2c binding much less, in agreement with the results of our tubulin co-sedimentation measurements. The specific location of the major MAP2c phosphorylation site in a region homologous to the muscarinic receptor-binding site of Tau suggests that MAP2c also may regulate processes other than microtubule dynamics.Cytoskeletal microtubule-associated proteins (MAPs) 3 are proteins of critical importance for regulating the stability and dynamics of microtubules (1). MAP2 and Tau represent MAP subfamilies expressed in neurons; MAP2 is localized in dendrites, whereas Tau is found mainly in axons (2). Tau and MAP2 belong to the class of intrinsically disordered proteins (IDPs), which lack a unique structure and which exist in multiple, quickly interconverting conformations (3-7). NMR is the method of choice for structural investigation of this type of protein. Tau and MAP2 differ in their N-terminal projection domains, which contain acidic and proline-rich subdomains, whereas the C-terminal parts, containing the microtubulebinding domain (MTBD) and the C-terminal region, are homologous (8). Tau is expressed in several splice variants. The human brain isoforms differ in the number of microtubulebinding regions (MTBRs) in the C-terminal portion and in the presence of two inserts near the N terminus. For the sake of simplicity, only the 441-residue variant lacking exons 6, 8, and 10 (9) is discussed in this paper. This variant has been studied in detail and was shown to form paired helical filaments and neurofibillary tangles in brains of patients suffering from Alzheimer's disease (10). The MAP2 family is composed of two high-molecular-weight proteins, MAP2a and MAP2b, each consisting of 1830 amino acids, and two low-molecular-weight proteins, MAP2c and MAP2d, consisting of 467 and 498 amino acids, respectively. The ...

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“…Phillips et al (1991) showed that myelin thickness as a function of axon diameter was decreased in alcohol-exposed rats from 10 to 90 days, indicating a permanent reduction in the relative thickness of myelin sheaths. After maternal alcohol administration the offspring also exhibited decreased expression of myelin basic protein (MBP) (Ozer and Halpain, 2000). The expression of MBP and myelin associated glycoprotein (MAG) was also affected by exposure to alcohol during postnatal development, especially during periods of rapid myelination (Zoeller et al, 1994).…”

Section: White Matter Constituents and Morphologymentioning

confidence: 99%

Interaction of Thiamine Deficiency and Voluntary Alcohol Consumption Disrupts Rat Corpus Callosum Ultrastructure

Sullivan

Stankovic

et al. 2007

Neuropsychopharmacol

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The relative roles of alcohol and thiamine deficiency in causing brain damage remain controversial in alcoholics without the WernickeKorsakoff syndrome. Experimental control over alcohol consumption and diet are impossible in humans but can be accomplished in animal models. This experiment was designed to differentiate the separate and combined effects on the macro-and ultrastructure of the corpus callosum of thiamine deficiency and voluntary alcohol consumption. Adult male alcohol-preferring (P) rats (9 chronically alcoholexposed and 9 water controls) received a thiamine-deficient diet for 2 weeks. There were four groups: five rats previously exposed to alcohol were treated with pyrithiamine (a thiamine phosphorylation inhibitor); five rats never exposed to alcohol were treated with pyrithiamine; four alcohol-exposed rats were treated with thiamine; and four rats never exposed to alcohol were treated with thiamine. On day 14, thiamine was restored in all 18 rats; 2 weeks later the 10 pyrithiamine-treated rats received intraperitoneal thiamine. The rats were perfused 61 days post-pyrithiamine treatment at age 598 days. Brains were dissected and weight and volumes were calculated. Sagittal sections were stained to measure white matter structures. The corpus callosum was examined using transmission electron microscopy to determine density of myelinated fibers, fiber diameter, and myelin thickness. The corpus callosum in the alcohol/ pyrithiamine group was significantly thinner, had greater fiber density, higher percentage of small fibers, and myelin thinning than in the alcohol/thiamine and water/thiamine groups. Several measures showed a graded effect, where the alcohol/pyrithiamine group had greater pathology than the water/pyrithiamine group, which had greater pathology than the two thiamine-replete groups. Across all 16 rats, thinner myelin sheaths correlated with higher percentage of small fibers. Myelin thickness and axon diameter together accounted for 71% of the variance associated with percentage of small fibers. Significant abnormalities in the alcohol/pyrithiamine group and lack of abnormality in the alcohol-exposed/thiamine-replete group indicate that thiamine deficiency caused white matter damage. The graded abnormalities across the dually to singly treated animals support a compounding effect of alcohol exposure and thiamine depletion, and indicate the potential for interaction between alcohol and thiamine deficiency in human alcohol-related brain damage.

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Phosphorylation-dependent Localization of Microtubule-associated Protein MAP2c to the Actin Cytoskeleton

Cited by 109 publications

References 48 publications

Doublecortin Association with Actin Filaments Is Regulated by Neurabin II

Doublecortin Association with Actin Filaments Is Regulated by Neurabin II

Quantitative mapping of microtubule-associated protein 2c (MAP2c) phosphorylation and regulatory protein 14-3-3ζ-binding sites reveals key differences between MAP2c and its homolog Tau

Interaction of Thiamine Deficiency and Voluntary Alcohol Consumption Disrupts Rat Corpus Callosum Ultrastructure

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