scholarly journals Actin dynamics regulate subcellular localization of the F-actin-binding protein PALLD in mouse Sertoli cells

Reproduction ◽  
2014 ◽  
Vol 148 (4) ◽  
pp. 333-341 ◽  
Author(s):  
Bryan A Niedenberger ◽  
Vesna A Chappell ◽  
Carol A Otey ◽  
Christopher B Geyer
Keyword(s):  
Subcellular Localization ◽  
Sertoli Cell ◽  
Nuclear Localization ◽  
Sertoli Cells ◽  
Binding Protein ◽  
Terminal Differentiation ◽  
Mutant Mice ◽  
Actin Binding ◽  
Actin Binding Protein ◽  
Receptor Mutant

Sertoli cells undergo terminal differentiation at puberty to support all phases of germ cell development, which occurs in the mouse beginning in the second week of life. By ∼18 dayspostpartum(dpp), nearly all Sertoli cells have ceased proliferation. This terminal differentiation is accompanied by the development of unique and regionally concentrated filamentous actin (F-actin) structures at the basal and apical aspects of the seminiferous epithelium, and this reorganization is likely to involve the action of actin-binding proteins. Palladin (PALLD) is a widely expressed F-actin-binding and bundling protein recently shown to regulate these structures, yet it is predominantly nuclear in Sertoli cells at puberty. We found that PALLD localized within nuclei of primary Sertoli cells grown in serum-free media but relocalized to the cytoplasm upon serum stimulation. We utilized this system within vivorelevance to Sertoli cell development to investigate mechanisms regulating nuclear localization of this F-actin-binding protein. Our results indicate that PALLD can be shuttled from the nucleus to the cytoplasm, and that this relocalization occurred following depolymerization of the F-actin cytoskeleton in response to cAMP signaling. Nuclear localization was reduced inHpg-mutant testes, suggesting the involvement of gonadotropin signaling. We found that PALLD nuclear localization was unaffected in testis tissues from LH receptor and androgen receptor-mutant mice. However, PALLD nuclear localization was reduced in the testes of FSH receptor-mutant mice, suggesting that FSH signaling during Sertoli cell maturation regulates this subcellular localization.

Identification and characterization of espin, an actin-binding protein localized to the F-actin-rich junctional plaques of Sertoli cell ectoplasmic specializations

1996 ◽  
Vol 109 (6) ◽  
pp. 1229-1239 ◽  
Author(s):  
J.R. Bartles ◽  
A. Wierda ◽  
L. Zheng
Keyword(s):  
Amino Acid ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Binding Protein ◽  
Sequence Similarity ◽  
Actin Binding ◽  
Immunogold Electron Microscopy ◽  
Actin Bundles ◽  
Actin Binding Protein

Ectoplasmic specializations are membrane-cytoskeletal assemblages found in Sertoli cells at sites of attachment to elongate spermatids or neighboring Sertoli cells. They are characterized in part by the presence of a unique junctional plaque which contains a narrow layer of parallel actin bundles sandwiched between the Sertoli cell plasma membrane and an affiliated cistern of endoplasmic reticulum. Using a monoclonal antibody, we have identified ‘espin,’ a novel actin-binding protein localized to ectoplasmic specializations. By immunogold electron microscopy, espin was localized to the parallel actin bundles of ectoplasmic specializations at sites where Sertoli cells contacted the heads of elongate spermatids. The protein was also detected at the sites of ectoplasmic specializations between neighboring Sertoli cells. Espin exhibits an apparent molecular mass of approximately 110 kDa in SDS gels. It is encoded by an approximately 2.9 kb mRNA, which was found to be specific to testis among the 11 rat organs and tissues examined. On the basis of cDNA sequence, espin is predicted to be an 836 amino acid protein which contains 8 ankyrin-like repeats in its N-terminal third, a potential P-loop, two proline-rich peptides and two peptides which contain clusters of multiple glutamates bracketed by arginines, lysines and glutamines in a pattern reminiscent of the repetitive motif found in the protein trichohyalin. The ankyrin-like repeats and a 66 amino acid peptide in the C terminus show significant sequence similarity to proteins encoded by the forked gene of Drosophila. A fusion protein containing the C-terminal 378 amino acids of espin was found to bind with high affinity (Kd = approximately 10 nM) to F-actin in vitro with a stoichiometry of approximately 1 espin per 6 actin monomers. When expressed by transfected NRK fibroblasts, the same C-terminal fragment of espin was observed to decorate actin fibers or cables. On the basis of its structure, localization and properties, we hypothesize that espin is involved in linking actin filaments to each other or to membranes, thereby potentially playing a key role in the organization and function of the ectoplasmic specialization.

scholarly journals Distinct regional and subcellular localization of the actin-binding protein filamin a in the mature rat brain

2012 ◽  
Vol 520 (13) ◽  
pp. 3013-3034 ◽  
Author(s):  
Yoav Noam ◽  
Lise Phan ◽  
Shawn McClelland ◽  
Erik M. Manders ◽  
Markus U. Ehrengruber ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Rat Brain ◽  
Binding Protein ◽  
Actin Binding ◽  
Filamin A ◽  
Actin Binding Protein

scholarly journals Filamin B represses chondrocyte hypertrophy in a Runx2/Smad3-dependent manner

2007 ◽  
Vol 178 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Lihua Zheng ◽  
Hwa-Jin Baek ◽  
Gerard Karsenty ◽  
Monica J. Justice
Keyword(s):  
Binding Protein ◽  
Mutant Mice ◽  
Actin Binding ◽  
Dependent Manner ◽  
Human Genetic Disease ◽  
Chondrocyte Hypertrophy ◽  
Actin Binding Protein ◽  
Ectopic Mineralization ◽  
Filamin B ◽  
Smad3 Phosphorylation

FILAMIN B, which encodes a cytoplasmic actin binding protein, is mutated in several skeletal dysplasias. To further investigate how an actin binding protein influences skeletogenesis, we generated mice lacking intact Filamin B. As observed in spondylocarpotarsal synostosis syndrome patients, Filamin B mutant mice display ectopic mineralization in many cartilaginous elements. This aberrant mineralization is due to ectopic chondrocyte hypertrophy similar to that seen in mice expressing Runx2 in chondrocytes. Accordingly, removing one copy of Runx2 rescues the Filamin B mutant phenotype, indicating that Filamin B is a regulator of Runx2 function during chondrocyte differentiation. Filamin B binds Smad3, which is known to interact with Runx2. Smad3 phosphorylation is increased in the mutant mice. Thus, Filamin B inhibits Runx2 activity, at least in part, through the Smad3 pathway. Our results uncover the involvement of actin binding proteins during chondrogenesis and provide a molecular basis to a human genetic disease.

scholarly journals A monopartite nuclear localization sequence regulates nuclear targeting of the actin binding protein myopodin

FEBS Letters ◽  
2005 ◽  
Vol 579 (29) ◽  
pp. 6673-6680 ◽  
Author(s):  
Ariane De Ganck ◽  
Thomas Hubert ◽  
Katrien Van Impe ◽  
Danny Geelen ◽  
Joël Vandekerckhove ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Binding Protein ◽  
Actin Binding ◽  
Nuclear Localization Sequence ◽  
Nuclear Targeting ◽  
Actin Binding Protein ◽  
Localization Sequence

Characterization of nuclear localization and nuclear export signals of yeast actin-binding protein Pan1

FEBS Letters ◽  
2007 ◽  
Vol 581 (28) ◽  
pp. 5371-5376 ◽  
Author(s):  
Joanna Kamińska ◽  
Magdalena Sędek ◽  
Monika Wysocka-Kapcińska ◽  
Teresa Żołądek
Keyword(s):  
Nuclear Localization ◽  
Nuclear Export ◽  
Binding Protein ◽  
Actin Binding ◽  
Actin Binding Protein

scholarly journals The Actin-Binding Protein Is Localized to Sertoli Cell Nuclei at Puberty.

2011 ◽  
Vol 85 (Suppl_1) ◽  
pp. 416-416
Author(s):  
Chris B. Geyer ◽  
Bryan A. Niedenberger ◽  
Vesna K. Chappell ◽  
Randall H. Renegar
Keyword(s):  
Sertoli Cell ◽  
Binding Protein ◽  
Actin Binding ◽  
Cell Nuclei ◽  
Actin Binding Protein

Clathrin Hub Expression Dissociates the Actin-Binding Protein Hip1R from Coated Pits and Disrupts Their Alignment with the Actin Cytoskeleton

Traffic ◽  
2001 ◽  
Vol 2 (11) ◽  
pp. 851-858 ◽  
Author(s):  
Elizabeth M. Bennett ◽  
Chih-Ying Chen ◽  
Asa E. Y. Engqvist-Goldstein ◽  
David G. Drubin ◽  
Frances M. Brodsky
Keyword(s):  
Actin Cytoskeleton ◽  
Binding Protein ◽  
Actin Binding ◽  
Coated Pits ◽  
Actin Binding Protein

Binding of Human Platelet Glycoprotein lb and Actin to Fragments of Actin-Binding Protein

1992 ◽  
Vol 67 (02) ◽  
pp. 252-257 ◽  
Author(s):  
Anne M Aakhus ◽  
J Michael Wilkinson ◽  
Nils Olav Solum
Keyword(s):  
Actin Filaments ◽  
High Speed ◽  
Binding Protein ◽  
Protein A ◽  
Actin Binding ◽  
Platelet Glycoprotein ◽  
Actin Binding Protein ◽  
Crossed Immunoelectrophoresis ◽  
Triton X ◽  
Calpain Inhibitors

SummaryActin-binding protein (ABP) is degraded into fragments of 190 and 90 kDa by calpain. A monoclonal antibody (MAb TI10) against the 90 kDa fragment of ABP coprecipitated with the glycoprotein lb (GP lb) peak observed on crossed immunoelectrophoresis of Triton X-100 extracts of platelets prepared without calpain inhibitors. MAb PM6/317 against the 190 kDa fragment was not coprecipitated with the GP lb peak under such conditions. The 90 kDa fragment was adsorbed on protein A agarose from extracts that had been preincubated with antibodies to GP lb. This supports the idea that the GP Ib-ABP interaction resides in the 90 kDa region of ABP. GP lb was sedimented with the Triton-insoluble actin filaments in trace amounts only, and only after high speed centrifugation (100,000 × g, 3 h). Both the 190 kDa and the 90 kDa fragments of ABP were sedimented with the Triton-insoluble actin filaments.

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