Nemaline Myopathy with Minicores Caused by Mutation of the CFL2 Gene Encoding the Skeletal Muscle Actin–Binding Protein, Cofilin-2

We have isolated cDNA clones on the basis of sequence similarity to the gene encoding the cyclic cAMP-binding protein CABP1 of Dictyostelium discoideum. The predicted amino acid sequence of the cloned cDNAs shows that the homology to CABP1 is restricted to a region rich in proline, glycine, glutamine, and tyrosine. Sequence comparison indicates that the cloned cDNAs encode the actin-binding protein p24. We have examined by RNA blot hybridization the expression of the gene encoding p24. For cells developed in suspension, the levels of p24 mRNA increase rapidly during early development, reaching a peak at 3–4 h. Addition of high concentrations of exogenous cAMP during the first 4 h of development produced little or no effect on the accumulation of p24 mRNA. Treatment with cAMP during subsequent stages of development reduced the levels of p24 mRNA. We attempted to determine if the synthesis of new proteins during early development is a requirement for the reduction in p24 mRNA levels by treating the cells with protein synthesis inhibitor. Unexpectedly, the addition of the inhibitor cycloheximide resulted in an increase in the level of p24 mRNA. The roles of cycloheximide and cAMP on the expression of the p24 gene are discussed.Key words: Dictyostelium discoideum, actin-binding protein, gene regulation, cAMP, cycloheximide.

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Syntrophin is an actin-binding protein the cellular localization of which is regulated through cytoskeletal reorganization in skeletal muscle cells

European Journal of Cell Biology ◽

10.1078/0171-9335-00415 ◽

2004 ◽

Vol 83 (10) ◽

pp. 555-565 ◽

Cited By ~ 19

Author(s):

Yuko Iwata ◽

Maurilio Sampaolesi ◽

Munekazu Shigekawa ◽

Shigeo Wakabayashi

Keyword(s):

Skeletal Muscle ◽

Cellular Localization ◽

Binding Protein ◽

Muscle Cells ◽

Skeletal Muscle Cells ◽

Actin Binding ◽

Cytoskeletal Reorganization ◽

Actin Binding Protein

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Identification of a high molecular weight actin-binding protein in skeletal muscle.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)37713-x ◽

1979 ◽

Vol 254 (6) ◽

pp. 1755-1758

Author(s):

P.J. Bechtel

Keyword(s):

Skeletal Muscle ◽

Molecular Weight ◽

High Molecular Weight ◽

Binding Protein ◽

Actin Binding ◽

Actin Binding Protein

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The PDZ Domain of the LIM Protein Enigma Binds to β-Tropomyosin

Molecular Biology of the Cell ◽

10.1091/mbc.10.6.1973 ◽

1999 ◽

Vol 10 (6) ◽

pp. 1973-1984 ◽

Cited By ~ 69

Author(s):

Pamela M. Guy ◽

Daryn A. Kenny ◽

Gordon N. Gill

Keyword(s):

Skeletal Muscle ◽

Family Member ◽

Actin Filaments ◽

Binding Protein ◽

Pdz Domain ◽

Actin Binding ◽

C2c12 Myotubes ◽

Lim Protein ◽

Actin Binding Protein ◽

Lim Domains

PDZ and LIM domains are modular protein interaction motifs present in proteins with diverse functions. Enigma is representative of a family of proteins composed of a series of conserved PDZ and LIM domains. The LIM domains of Enigma and its most related family member, Enigma homology protein, bind to protein kinases, whereas the PDZ domains of Enigma and family member actin-associated LIM protein bind to actin filaments. Enigma localizes to actin filaments in fibroblasts via its PDZ domain, and actin-associated LIM protein binds to and colocalizes with the actin-binding protein α-actinin-2 at Z lines in skeletal muscle. We show that Enigma is present at the Z line in skeletal muscle and that the PDZ domain of Enigma binds to a skeletal muscle target, the actin-binding protein tropomyosin (skeletal β-TM). The interaction between Enigma and skeletal β-TM was specific for the PDZ domain of Enigma, was abolished by mutations in the PDZ domain, and required the PDZ-binding consensus sequence (Thr-Ser-Leu) at the extreme carboxyl terminus of skeletal β-TM. Enigma interacted with isoforms of tropomyosin expressed in C2C12 myotubes and formed an immunoprecipitable complex with skeletal β-TM in transfected cells. The association of Enigma with skeletal β-TM suggests a role for Enigma as an adapter protein that directs LIM-binding proteins to actin filaments of muscle cells.

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Identification and characterization of a low temperature regulated gene encoding an actin-binding protein from wheat

FEBS Letters ◽

10.1016/0014-5793(96)00599-6 ◽

1996 ◽

Vol 389 (3) ◽

pp. 324-327 ◽

Cited By ~ 32

Author(s):

Jean Danyluk ◽

Eric Carpentier ◽

Fathey Sarhan

Keyword(s):

Low Temperature ◽

Binding Protein ◽

Actin Binding ◽

Gene Encoding ◽

Actin Binding Protein ◽

Identification And Characterization

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Xin, an actin binding protein, is expressed within muscle satellite cells and newly regenerated skeletal muscle fibers

AJP Cell Physiology ◽

10.1152/ajpcell.00124.2007 ◽

2007 ◽

Vol 293 (5) ◽

pp. C1636-C1644 ◽

Cited By ~ 29

Author(s):

Thomas J. Hawke ◽

Daniel J. Atkinson ◽

Shane B. Kanatous ◽

Peter F. M. Van der Ven ◽

Sean C. Goetsch ◽

...

Keyword(s):

Skeletal Muscle ◽

Satellite Cell ◽

Satellite Cells ◽

Myogenic Differentiation ◽

Binding Protein ◽

Skeletal Muscle Regeneration ◽

Actin Binding ◽

Skeletal Muscle Myosin ◽

Muscle Satellite Cells ◽

Actin Binding Protein

Xin is a muscle-specific actin binding protein of which its role and regulation within skeletal muscle is not well understood. Here we demonstrate that Xin mRNA is robustly upregulated (>16-fold) within 12 h of skeletal muscle injury and is localized to the muscle satellite cell population. RT-PCR confirmed the expression pattern of Xin during regeneration, as well as within primary muscle myoblast cultures, but not other known stem cell populations. Immunohistochemical staining of single myofibers demonstrate Xin expression colocalized with the satellite cell marker Syndecan-4 further supporting the mRNA expression of Xin in satellite cells. In situ hybridization of regenerating muscle 5–7 days postinjury illustrates Xin expression within newly regenerated myofibers. Promoter-reporter assays demonstrate that known myogenic transcription factors [myocyte enhancer factor-2 (MEF2), myogenic differentiation-1 (MyoD), and myogenic factor-5 (Myf-5)] transactivate Xin promoter constructs supporting the muscle-specific expression of Xin. To determine the role of Xin within muscle precursor cells, proliferation, migration, and differentiation analysis using Xin, short hairpin RNA (shRNA) were undertaken in C2C12 myoblasts. Reducing endogenous Xin expression resulted in a 26% increase ( P < 0.05) in cell proliferation and a 20% increase ( P < 0.05) in myoblast migratory capacity. Skeletal muscle myosin heavy chain protein levels were increased ( P < 0.05) with Xin shRNA administration; however, this was not accompanied by changes in myoglobin protein (another marker of differentiation) nor overt morphological differences relative to differentiating control cells. Taken together, the present findings support the hypothesis that Xin is expressed within muscle satellite cells during skeletal muscle regeneration and is involved in the regulation of myoblast function.

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