Microtubule-associated protein-2 located in growth regions of rat hippocampal neurons is highly phosphorylated at its proline-rich region

AbstractTau is a microtubule (MT)-associated protein, which precisely localizes to the axon of a mature neuron. Although it has been widely used as an axonal marker, the mechanisms for its axonal localization have been elusive. This might be largely due to the lack of an experimental system, as exogenously expressed tau, such as GFP-tau, mis-localizes to the soma and dendrites. In this study, we found that the expression of endogenous tau and its axonal localization in cultured rat hippocampal neurons mainly occur during early neuronal development and are coupled. By mimicking this early expression, we demonstrate that exogenously expressed human tau can be properly localized to the axon, thereby providing the first experimental model to study the mechanisms of tau localization. Using this model, we obtained surprising findings that the axonal localization of tau did not require the MT-binding domain nor correlate with the MT-binding ability. Instead, we identified a transport mechanism mediated by the proline-rich region 2 (PRR2), which contains a number of important phosphorylation sites. Mimicking phosphorylation and dephosphorylation in PRR2 disrupts the axonal localization, suggesting that it is regulated by the phosphorylation state of PRR2. These results shed new lights on the mechanism for the axonal localization of tau and indicate a link between the hyperphosphorylation and mis-localization of tau observed in tauopathies.Significance statementIn this paper, we present a first experimental system, in which expressed tau is properly localized to the axon, and which can therefore be used to study the mechanisms of tau localization and mis-localization. Using this system, we provide evidence that the microtubule binding domain of tau nor stable binding of tau to microtubules is not necessary for its axonal localization. Instead, we identified the proline-rich region and its phosphorylation-state dictate the localization of tau in neurons. These results provide a novel foundation to consider how axonal tau mis-localize to the soma and dendrites during early pathogenesis of Alzheimer’s disease.

Download Full-text

Regulatory mechanisms for the axonal localization of tau protein in neurons

Molecular Biology of the Cell ◽

10.1091/mbc.e19-03-0183 ◽

2019 ◽

Vol 30 (19) ◽

pp. 2441-2457 ◽

Cited By ~ 6

Author(s):

Minori Iwata ◽

Shoji Watanabe ◽

Ayaka Yamane ◽

Tomohiro Miyasaka ◽

Hiroaki Misonou

Keyword(s):

Tau Protein ◽

Hippocampal Neurons ◽

Neuronal Development ◽

Tight Binding ◽

Regulatory Mechanisms ◽

Rich Region ◽

Mature Neurons ◽

Developing Neurons ◽

Surprising Finding ◽

Proline Rich Region

Tau is a microtubule (MT)-associated protein that is thought to be localized to the axon. However, its precise localization in developing neurons and mechanisms for the axonal localization have not been fully addressed. In this study, we found that the axonal localization of tau in cultured rat hippocampal neurons mainly occur during early neuronal development. Interestingly, transient expression of human tau in very immature neurons, but not in mature neurons, mimicked the developmental localization of endogenous tau to the axon. We therefore were able to establish an experimental model, in which exogenously expressed tau can be properly localized to the axon. Using this model, we obtained a surprising finding that the axonal localization of tau did not require stable MT binding. Tau lacking the MT-binding domain (MTBD) exhibited high diffusivity but localized properly to the axon. In contrast, a dephosphorylation-mimetic mutant of the proline-rich region 2 showed reinforced MT binding and mislocalization. Our results suggest that tight binding to MTs prevents tau from entering the axon and results in mislocalization in the soma and dendrites when expressed in mature neurons. This study therefore provides a novel mechanism independent of MTBD for the axonal localization of tau.

Download Full-text

Structural characterization by nuclear magnetic resonance of the impact of phosphorylation in the proline-rich region of the disordered Tau protein

Proteins Structure Function and Bioinformatics ◽

10.1002/prot.23210 ◽

2011 ◽

Vol 80 (2) ◽

pp. 454-462 ◽

Cited By ~ 54

Author(s):

Nathalie Sibille ◽

Isabelle Huvent ◽

Caroline Fauquant ◽

Dries Verdegem ◽

Laziza Amniai ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Structural Characterization ◽

Tau Protein ◽

Rich Region ◽

The Impact ◽

Proline Rich Region ◽

Nuclear Magnetic

Download Full-text

Vaccine-induced, but not natural immunity, against the Streptococcal inhibitor of complement protects against invasive disease

npj Vaccines ◽

10.1038/s41541-021-00326-3 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Lionel K. K. Tan ◽

Mark Reglinski ◽

Daryl Teo ◽

Nada Reza ◽

Lucy E. M. Lamb ◽

...

Keyword(s):

Ex Vivo ◽

Natural Infection ◽

Invasive Disease ◽

Full Length ◽

Natural Immunity ◽

Rich Region ◽

Antibody Recognition ◽

Naturally Occurring ◽

Protective Antibodies ◽

Proline Rich Region

AbstractHighly pathogenic emm1 Streptococcus pyogenes strains secrete the multidomain Streptococcal inhibitor of complement (SIC) that binds and inactivates components of the innate immune response. We aimed to determine if naturally occurring or vaccine-induced antibodies to SIC are protective against invasive S. pyogenes infection. Immunisation with full-length SIC protected mice against systemic bacterial dissemination following intranasal or intramuscular infection with emm1 S. pyogenes. Vaccine-induced rabbit anti-SIC antibodies, but not naturally occurring human anti-SIC antibodies, enhanced bacterial clearance in an ex vivo whole-blood assay. SIC vaccination of both mice and rabbits resulted in antibody recognition of all domains of SIC, whereas naturally occurring human anti-SIC antibodies recognised the proline-rich region of SIC only. We, therefore, propose a model whereby natural infection with S. pyogenes generates non-protective antibodies against the proline-rich region of SIC, while vaccination with full-length SIC permits the development of protective antibodies against all SIC domains.

Download Full-text

A Proline-Rich Region in the Zeste Protein Essential for Transvection and white Repression by Zeste1

Genetics ◽

10.1093/genetics/148.4.1865 ◽

1998 ◽

Vol 148 (4) ◽

pp. 1865-1874

Author(s):

Christina Rosen ◽

Dale Dorsett ◽

Joseph Jack

Keyword(s):

Dna Binding ◽

Protein Interactions ◽

Homologous Chromosome ◽

Protein Complexes ◽

Dna Binding Protein ◽

Polycomb Group ◽

The Self ◽

Rich Region ◽

Interaction Domain ◽

Proline Rich Region

Abstract The DNA-binding protein encoded by the zeste gene of Drosophila activates transcription and mediates interchromosomal interactions such as transvection. The mutant protein encoded by the zeste1 (z1) allele retains the ability to support transvection, but represses white. Similar to transvection, repression requires Zeste-Zeste protein interactions and a second copy of white, either on the homologous chromosome or adjacent on the same chromosome. We characterized two pseudorevertants of z1 (z1-35 and z1-42) and another zeste mutation (z78c) that represses white. The z1 lesion alters a lysine residue located between the N-terminal DNA-binding domain and the C-terminal hydrophobic repeats involved in Zeste self-interactions. The z78c mutation alters a histidine near the site of the z1 lesion. Both z1 pseudorevertants retain the z1 lesion and alter different prolines in a proline-rich region located between the z1 lesion and the self-interaction domain. The pseudorevertants retain the ability to self-interact, but fail to repress white or support transvection at Ultrabithorax. To account for these observations and evidence indicating that Zeste affects gene expression through Polycomb group (Pc-G) protein complexes that epigenetically maintain chromatin states, we suggest that the regions affected by the z1, z78c, and pseudorevertant lesions mediate interactions between Zeste and the maintenance complexes.

Download Full-text

Identification of amino acid residues required for a specific interaction between Src-tyrosine kinase and proline-rich region of phosphatidylinositol-3′ kinase

FEBS Letters ◽

10.1016/s0014-5793(96)01179-9 ◽

1996 ◽

Vol 397 (2-3) ◽

pp. 183-185 ◽

Cited By ~ 12

Author(s):

Paul Mak ◽

Zhiqing He ◽

Tomohiro Kurosaki

Keyword(s):

Amino Acid ◽

Tyrosine Kinase ◽

Specific Interaction ◽

Amino Acid Residues ◽

Phosphatidylinositol 3 Kinase ◽

Rich Region ◽

Src Tyrosine Kinase ◽

Proline Rich Region ◽

Phosphatidylinositol 3

Download Full-text

Identification and functional characterization of a novel human protein highly related to the yeast dynamin-like GTPase Vps1p

Journal of Cell Science ◽

10.1242/jcs.111.10.1341 ◽

1998 ◽

Vol 111 (10) ◽

pp. 1341-1349 ◽

Cited By ~ 3

Author(s):

M. Imoto ◽

I. Tachibana ◽

R. Urrutia

Keyword(s):

Endoplasmic Reticulum ◽

Cho Cells ◽

Mammalian Cells ◽

Functional Characterization ◽

Luciferase Reporter ◽

Pleckstrin Homology ◽

Rich Region ◽

Gtpase Domain ◽

Proline Rich Region

Dynamin proteins containing a GTPase domain, a pleckstrin homology motif and a proline-rich tail participate in receptor-mediated endocytosis in organisms ranging from insects to vertebrates. In addition, dynamin-related GTPases, such as the yeast Golgi protein Vps1p, which lack both the pleckstrin homology motif and the proline-rich region, participate in vesicular transport within the secretory pathway in lower eukaryotes. However, no data is available on the existence of Vps1p-like proteins in mammalian cells. In this study, we report the identification and characterization of a novel gene encoding a human dynamin-related protein, DRP1, displaying high similarity to the Golgi dynamin-like protein Vps1p from yeast and to a Caenorhabditis elegans protein deposited in the databank. These proteins are highly conserved in their N-terminal tripartite GTPase domain but lack the pleckstrin homology motif and proline-rich region. Northern blot analysis reveals that the DRP1 mRNA is detected at high levels in human muscle, heart, kidney and brain. Immunolocalization studies in Chinese hamster ovary (CHO) cells using an epitope-tagged form of DRP1 and confocal microscopy show that this protein is concentrated in a perinuclear region that labels with the endoplasmic reticulum marker DiOC6(3) and the Golgi marker C5-DMB-Cer. In addition, the localization of DRP1 is highly similar to the localization of the endoplasmic reticulum and cis-Golgi GTPase Rab1A, but not to the staining for the trans-Golgi GTPase Rab6. Furthermore, overexpression of a cDNA encoding a GTP binding site mutant of DRP1 (DRP1(K38E)) in CHO cells decreases the amount of a secreted luciferase reporter protein, whereas the overexpression of wild-type DRP1 increases the secretion of this marker. Together, these results constitute the first structural and functional characterization of a mammalian protein similar to the yeast dynamin-related GTPase Vps1p and indicate that the participation of these proteins in secretion has been conserved throughout evolution.

Download Full-text