Actin-binding Protein Drebrin Regulates HIV-1-triggered Actin Polymerization and Viral Infection

Branching filaments with striking perpendicularity form when actin polymerizes in the presence of macrophage actin-binding protein. Actin-binding protein molecules are visible at the branch points. Compared with actin polymerized in the absence of actin-binding proteins, not only do the filaments branch but the average length of the actin filaments decreases from 3.2 to 0.63 micrometer. Arrowhead complexes formed by addition of heavy meromyosin molecules to the branching actin filaments point toward the branch points. Actin-binding protein also accelerates the onset of actin polymerization. All of these findings show that actin filaments assemble from nucleating sites on actin-binding protein dimers. A branching polymerization of actin filaments from a preexisting lattice of actin filaments joined by actin-binding protein molecules could generate expansion of cortical cytoplasm in amoeboid cells.

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The heat shock cognate protein from Dictyostelium affects actin polymerization through interaction with the actin-binding protein cap32/34.

The EMBO Journal ◽

10.1002/j.1460-2075.1993.tb06054.x ◽

1993 ◽

Vol 12 (10) ◽

pp. 3763-3771 ◽

Cited By ~ 38

Author(s):

U. Haus ◽

P. Trommler ◽

P.R. Fisher ◽

H. Hartmann ◽

F. Lottspeich ◽

...

Keyword(s):

Heat Shock ◽

Actin Polymerization ◽

Binding Protein ◽

Actin Binding ◽

Actin Binding Protein ◽

Heat Shock Cognate Protein ◽

Cognate Protein

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IDENTIFICATION OF GLYCOPROTEIN Ib8 AS THE Mr = 24,000 PLATELET POLYPEPTIDE PHOSPHORYLATED BY AGENTS THAT ELEVATE CYCLIC AMP

10.1055/s-0038-1642926 ◽

1987 ◽

Cited By ~ 1

Author(s):

J E B Fox ◽

C C Reynolds ◽

J K Boyles ◽

R A Abel ◽

M M Johnson

Keyword(s):

Cyclic Amp ◽

Platelet Function ◽

Actin Polymerization ◽

Binding Protein ◽

Membrane Skeleton ◽

Actin Binding ◽

Inhibitory Effects ◽

Actin Binding Protein ◽

Triton X ◽

Β Chain

Platelet function is inhibited by agents that elevate intracellular cyclic AMP concentrations, presumably as a result of the cyclic AMP-stimulated phosphorylation of intracellular proteins. Polypeptides that become phosphorylated are of Mr = 250,000, Mr = 51.000 (P51), Mr = 36,000 (P36), Mr = 24,000 (P24), and Mr = 22.000 (P22). The Mr = 250,000 polypeptide is actin-binding protein, but the identity of the other polypeptides 1s unknown. In the present study, we identified the P24 polypeptide. Platelets were radiolabeled with [32P]P1 and then Incubated for 2-5 min in the presence or absence of 5 μM prostaglandin E1 (PGE1). The PGE1-induced phosphorylation of P24 was detected on autoradiograms of SDS-gels. Since P24 has been shown to be membrane-associated, its molecular weight was compared with those of known membrane proteins. P24 comigrated with the β-chain of purified GP Ib on reduced gels (Mr = 24,000) and also on nonreduced gels (when GP Ibβ is disulfide-linked to GP Ibα and migrates with Mr = 170,000). Like GP Ibβ, P24 was associated with actin filaments in Triton X-100 lysates. Both GP Ibβ and P24 were selectively associated with filaments of the membrane skeleton and were released from filaments when the Ca2+-dependent protease was active. Antibodies against GP Ib immunoprecipitated P24 from platelet lysates. Finally, exposure of Bernard-Soulier platelets (that lacked GP Ib) to PGE1 resulted in phosphorylation of actin-binding protein, P51, P36, and P22, but not P24. We conclude that P24 is GP Ibβ. To determine whether phosphorylation of GP Ibβ is responsible for the inhibitory effects of PGE1 on platelets, we compared the action of PGE1 on control platelets with that on Bernard-Soulier platelets. One of the ways in which PGE1 inhibits platelet activation is by inhibiting the polymerization of actin. While PGE1 inhibited actin polymerization in control platelets, it did not in Bernard-Soulier platelets. We conclude that GP Ibβ is phosphorylated by agents that elevate cyclic AMP and that phosphorylation of this glycoprotein results in inhibition of platelet function.

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The 47-kD protein increased in neutrophil actin dysfunction with 47- and 89-kD protein abnormalities is lymphocyte-specific protein

Blood ◽

10.1182/blood.v83.1.231.bloodjournal831231 ◽

1994 ◽

Vol 83 (1) ◽

pp. 231-241 ◽

Cited By ~ 1

Author(s):

T Howard ◽

Y Li ◽

M Torres ◽

A Guerrero ◽

T Coates

Keyword(s):

Actin Polymerization ◽

Binding Protein ◽

Family Members ◽

Autosomal Recessive Disorder ◽

Specific Protein ◽

Polymorphonuclear Neutrophils ◽

Actin Binding ◽

Expression Library ◽

Actin Binding Protein ◽

Formyl Peptide

A male child born of related parents suffered recurrent infections because of neutrophil actin dysfunction with increased amounts of a 47- kD protein and decreased amounts of an 89-kD protein (NAD 47/89). The patient and family members were studied to define the nature of the abnormal proteins and to examine their role in the functional defects of neutrophil actin dysfunction (NAD) 47/89 polymorphonuclear neutrophils (PMNs). NAD 47/89 PMNs are defective in motility, microfilamentous cytoskeletal structure, and formyl peptide-induced actin polymerization and express increased amounts of a 47-kD protein and decreased amounts of an 89-kD proteins intermediate abnormality in amount of 47-kD and 89-kD proteins in PMNs from parents and a female sibling suggest the disease is an autosomal recessive disorder. Immunoblots with monoclonal antibody (MoAb1) and polyclonal antibody raised to 47-kD protein showed the 89-kD protein is antigenically distinct from the 47-kD protein and the 89-kD protein is not gelsolin. 125I-actin binding to one-dimensional (1 D) and 2 D gels of PMN proteins from NAD 47/89 proband, family members, and controls showed the 47-kD protein binds actin, is acidic (pl = 4.5 to 4.7), is recognized by the MoAb1, exists on 2-D gels as three distinct actin binding species (MWapp 52 kD, 47-kD, and 44-kD), and is present in control PMNs in lesser amount than in PMNs of NAD 47/89 proband or parents. Immunoaffinity purification of the 47 kD actin binding protein on MoAb1 matrix yielded a multimolecular complex with proteins of MWapp 180 kD, 71 kD, 47 kD and actin. Cloning, sequencing, and expression of a 1.58-kb cDNA selected for MoAb1 reactivity from a HL60 expression library and microsequence of native PMNs, 47-kD actin binding protein showed the overexpressed 47-kD protein is lymphocyte-specific protein 1 (LSP1), which is a known actin binding protein. The results show LSP1 is expressed in PMNs and suggest overexpression of LSP1 is related to the motility and cytoskeletal abnormalities in NAD 47/89 PMNs.

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LATS1 tumor suppressor is a novel actin-binding protein and negative regulator of actin polymerization

Cell Research ◽

10.1038/cr.2011.122 ◽

2011 ◽

Vol 21 (10) ◽

pp. 1513-1516 ◽

Cited By ~ 28

Author(s):

Stacy Visser-Grieve ◽

Zhonghua Zhou ◽

Yi-Min She ◽

He Huang ◽

Terry D Cyr ◽

...

Keyword(s):

Tumor Suppressor ◽

Actin Polymerization ◽

Binding Protein ◽

Negative Regulator ◽

Actin Binding ◽

Actin Binding Protein

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Filamin, a high relative molecular mass actin-binding protein from smooth muscles, promotes actin polymerization

FEBS Letters ◽

10.1016/0014-5793(81)81222-7 ◽

1981 ◽

Vol 136 (1) ◽

pp. 98-100 ◽

Cited By ~ 6

Author(s):

V.E. Koteliansky ◽

V.P. Shirinsky ◽

G.N. Gneushev ◽

V.N. Smirnov

Keyword(s):

Molecular Mass ◽

Actin Polymerization ◽

Binding Protein ◽

Smooth Muscles ◽

Actin Binding ◽

Relative Molecular Mass ◽

Filamin A ◽

Actin Binding Protein

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Toxofilin, a Novel Actin-binding Protein from Toxoplasma gondii, Sequesters Actin Monomers and Caps Actin Filaments

Molecular Biology of the Cell ◽

10.1091/mbc.11.1.355 ◽

2000 ◽

Vol 11 (1) ◽

pp. 355-368 ◽

Cited By ~ 58

Author(s):

Olivier Poupel ◽

Haralabia Boleti ◽

Sophie Axisa ◽

Evelyne Couture-Tosi ◽

Isabelle Tardieux

Keyword(s):

Green Fluorescent Protein ◽

Toxoplasma Gondii ◽

Host Cell ◽

Actin Filaments ◽

Actin Polymerization ◽

Fluorescent Protein ◽

Binding Protein ◽

Actin Binding ◽

Actin Binding Protein ◽

Green Fluorescent

Toxoplasma gondii relies on its actin cytoskeleton to glide and enter its host cell. However, T. gondii tachyzoites are known to display a strikingly low amount of actin filaments, which suggests that sequestration of actin monomers could play a key role in parasite actin dynamics. We isolated a 27-kDa tachyzoite protein on the basis of its ability to bind muscle G-actin and demonstrated that it interacts with parasite G-actin. Cloning and sequence analysis of the gene coding for this protein, which we named Toxofilin, showed that it is a novel actin-binding protein. In in vitro assays, Toxofilin not only bound to G-actin and inhibited actin polymerization as an actin-sequestering protein but also slowed down F-actin disassembly through a filament end capping activity. In addition, when green fluorescent protein-tagged Toxofilin was overexpressed in mammalian nonmuscle cells, the dynamics of actin stress fibers was drastically impaired, whereas green fluorescent protein-Toxofilin copurified with G-actin. Finally, in motile parasites, during gliding or host cell entry, Toxofilin was localized in the entire cytoplasm, including the rear end of the parasite, whereas in intracellular tachyzoites, especially before they exit from the parasitophorous vacuole of their host cell, Toxofilin was found to be restricted to the apical end.

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The 47-kD protein increased in neutrophil actin dysfunction with 47- and 89-kD protein abnormalities is lymphocyte-specific protein

Blood ◽

10.1182/blood.v83.1.231.231 ◽

1994 ◽

Vol 83 (1) ◽

pp. 231-241 ◽

Cited By ~ 39

Author(s):

T Howard ◽

Y Li ◽

M Torres ◽

A Guerrero ◽

T Coates

Keyword(s):

Actin Polymerization ◽

Binding Protein ◽

Family Members ◽

Autosomal Recessive Disorder ◽

Specific Protein ◽

Polymorphonuclear Neutrophils ◽

Actin Binding ◽

Expression Library ◽

Actin Binding Protein ◽

Formyl Peptide

Abstract A male child born of related parents suffered recurrent infections because of neutrophil actin dysfunction with increased amounts of a 47- kD protein and decreased amounts of an 89-kD protein (NAD 47/89). The patient and family members were studied to define the nature of the abnormal proteins and to examine their role in the functional defects of neutrophil actin dysfunction (NAD) 47/89 polymorphonuclear neutrophils (PMNs). NAD 47/89 PMNs are defective in motility, microfilamentous cytoskeletal structure, and formyl peptide-induced actin polymerization and express increased amounts of a 47-kD protein and decreased amounts of an 89-kD proteins intermediate abnormality in amount of 47-kD and 89-kD proteins in PMNs from parents and a female sibling suggest the disease is an autosomal recessive disorder. Immunoblots with monoclonal antibody (MoAb1) and polyclonal antibody raised to 47-kD protein showed the 89-kD protein is antigenically distinct from the 47-kD protein and the 89-kD protein is not gelsolin. 125I-actin binding to one-dimensional (1 D) and 2 D gels of PMN proteins from NAD 47/89 proband, family members, and controls showed the 47-kD protein binds actin, is acidic (pl = 4.5 to 4.7), is recognized by the MoAb1, exists on 2-D gels as three distinct actin binding species (MWapp 52 kD, 47-kD, and 44-kD), and is present in control PMNs in lesser amount than in PMNs of NAD 47/89 proband or parents. Immunoaffinity purification of the 47 kD actin binding protein on MoAb1 matrix yielded a multimolecular complex with proteins of MWapp 180 kD, 71 kD, 47 kD and actin. Cloning, sequencing, and expression of a 1.58-kb cDNA selected for MoAb1 reactivity from a HL60 expression library and microsequence of native PMNs, 47-kD actin binding protein showed the overexpressed 47-kD protein is lymphocyte-specific protein 1 (LSP1), which is a known actin binding protein. The results show LSP1 is expressed in PMNs and suggest overexpression of LSP1 is related to the motility and cytoskeletal abnormalities in NAD 47/89 PMNs.

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