scholarly journals Drosophila myoblast city Encodes a Conserved Protein That Is Essential for Myoblast Fusion, Dorsal Closure, and Cytoskeletal Organization

1997 ◽  
Vol 138 (3) ◽  
pp. 589-603 ◽  
Author(s):  
Mary Ruth S. Erickson ◽  
Brian J. Galletta ◽  
Susan M. Abmayr
Keyword(s):  
Signal Transduction ◽  
Signal Transduction Pathway ◽  
Focal Adhesions ◽  
Myoblast Fusion ◽  
Dorsal Closure ◽  
Cytoskeletal Organization ◽  
Visceral Mesoderm ◽  
Isolation And Characterization ◽  
Pole Cells

The Drosophila myoblast city (mbc) locus was previously identified on the basis of a defect in myoblast fusion (Rushton et al., 1995. Development [Camb.]. 121:1979–1988). We describe herein the isolation and characterization of the mbc gene. The mbc transcript and its encoded protein are expressed in a broad range of tissues, including somatic myoblasts, cardial cells, and visceral mesoderm. It is also expressed in the pole cells and in ectodermally derived tissues, including the epidermis. Consistent with this latter expression, mbc mutant embryos exhibit defects in dorsal closure and cytoskeletal organization in the migrating epidermis. Both the mesodermal and ectodermal defects are reminiscent of those induced by altered forms of Drac1 and suggest that mbc may function in the same pathway. MBC bears striking homology to human DOCK180, which interacts with the SH2-SH3 adapter protein Crk and may play a role in signal transduction from focal adhesions. Taken together, these results suggest the possibility that MBC is an intermediate in a signal transduction pathway from the rho/rac family of GTPases to events in the cytoskeleton and that this pathway may be used during myoblast fusion and dorsal closure.

Isolation and characterization of A T lymphocyte mutant defective in the protein kinase C signal transduction pathway

1991 ◽  
Vol 28 (9) ◽  
pp. 921-929 ◽  
Author(s):  
Jean-François Peyron ◽  
Jean-François Tanti ◽  
Martine Limouse ◽  
Dariush Farahifar ◽  
Patrick Auberger ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
T Lymphocyte ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Isolation And Characterization ◽  
Kinase C

scholarly journals Isolation and characterization of four ethylene signal transduction elements in plums (Prunus salicina L.)

2007 ◽  
Vol 58 (13) ◽  
pp. 3631-3643 ◽  
Author(s):  
I. El-Sharkawy ◽  
W. S. Kim ◽  
A. El-Kereamy ◽  
S. Jayasankar ◽  
A. M. Svircev ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Prunus Salicina ◽  
Isolation And Characterization ◽  
Ethylene Signal Transduction ◽  
Ethylene Signal

Abstract 741: Characterization of high-grade serous ovarian carcinoma by measuring functional signal transduction pathway activity

2021 ◽  
Author(s):  
Phyllis van der Ploeg ◽  
Laura van Lieshout ◽  
Yvonne Wesseling-Rozendaal ◽  
Anja van de Stolpe ◽  
Diederick Keizer ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Ovarian Carcinoma ◽  
Signal Transduction Pathway ◽  
High Grade ◽  
Transduction Pathway ◽  
Pathway Activity ◽  
Serous Ovarian Carcinoma

scholarly journals Isolation and characterization of a B lymphocyte mutant with altered signal transduction through its antigen receptor.

1989 ◽  
Vol 169 (3) ◽  
pp. 1059-1070 ◽  
Author(s):  
J G Monroe ◽  
V L Seyfert ◽  
C S Owen ◽  
N Sykes
Keyword(s):  
Signal Transduction ◽  
B Lymphocyte ◽  
Protein Activation ◽  
Phospholipid Hydrolysis ◽  
Isolation And Characterization ◽  
G Protein Activation ◽  
Wehi 231 ◽  
Inositol Phospholipid ◽  
Pi Hydrolysis

A receptor surface Ig (sIg) signaling variant of WEHI-231 was constructed to investigate components and linkages between various signaling events associated with signal transduction through sIg. Unlike the wildtype, crosslinking of sIgM on VS2.12-cl.2 did not result in downregulation of proliferation. Similarly, receptor crosslinking was uncoupled from inositol phospholipid (PI) hydrolysis and upregulation of c-fos expression in the variant. The signaling defect in VS2.12-cl.2 appears to be proximal to phospholipase C activation as direct G protein activation by A1F4- triggers PI hydrolysis and bypassing PI hydrolysis using phorbol diester stimulation of protein kinase C restores the inhibitable phenotype and the ability to upregulate c-fos. Even more interesting, sIg-linked Ca2+ responses by VS2.12-cl.2 are equivalent to these observed in the wildtype WEHI-231. These latter results suggest that contrary to current thought, sIg-generated signals may not be coupled to Ca2+ fluxes entirely via inositol phospholipid hydrolysis. Thus, VS2.12-cl.2 is a new and powerful tool with which to analyze signaling through sIg at the molecular level.

scholarly journals A RANK/TRAF6-dependent Signal Transduction Pathway Is Essential for Osteoclast Cytoskeletal Organization and Resorptive Function

2002 ◽  
Vol 277 (46) ◽  
pp. 44347-44356 ◽  
Author(s):  
Allison P. Armstrong ◽  
Mark E. Tometsko ◽  
Moira Glaccum ◽  
Claire L. Sutherland ◽  
David Cosman ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Cytoskeletal Organization ◽  
Dependent Signal

scholarly journals Isolation and Characterization of Effector-Loop Mutants ofCDC42in Yeast

2001 ◽  
Vol 12 (5) ◽  
pp. 1239-1255 ◽  
Author(s):  
Amy S. Gladfelter ◽  
John J. Moskow ◽  
Trevin R. Zyla ◽  
Daniel J. Lew
Keyword(s):  
Cell Polarity ◽  
Small Gtpases ◽  
Small Gtpase ◽  
Cytoskeletal Organization ◽  
Cell Behaviors ◽  
Isolation And Characterization ◽  
Starting Point ◽  
Effector Pathways

The highly conserved small GTPase Cdc42p is a key regulator of cell polarity and cytoskeletal organization in eukaryotic cells. Multiple effectors of Cdc42p have been identified, although it is unclear how their activities are coordinated to produce particular cell behaviors. One strategy used to address the contributions made by different effector pathways downstream of small GTPases has been the use of “effector-loop” mutants of the GTPase that selectively impair only a subset of effector pathways. We now report the generation and preliminary characterization of a set of effector-loop mutants ofSaccharomyces cerevisiae CDC42. These mutants define genetically separable pathways influencing actin or septin organization. We have characterized the phenotypic defects of these mutants and the binding defects of the encoded proteins to known yeast Cdc42p effectors in vitro. The results suggest that these effectors cannot account for the observed phenotypes, and therefore that unknown effectors exist that affect both actin and septin organization. The availability of partial function alleles of CDC42 in a genetically tractable system serves as a useful starting point for genetic approaches to identify such novel effectors.

scholarly journals Genetic evidence for signal transduction within the Bacillus subtilis GerA germinant receptor

2021 ◽  
Author(s):  
Jeremy D. Amon ◽  
Lior Artzi ◽  
David Z. Rudner
Keyword(s):  
Signal Transduction ◽  
Bacillus Subtilis ◽  
Signal Transduction Pathway ◽  
Dominant Negative ◽  
Transduction Pathway ◽  
Sense And Respond ◽  
Enrichment Strategy ◽  
Functional Receptor

Bacterial spores can rapidly exit dormancy through the process of germination. This process begins with the activation of nutrient receptors embedded in the spore membrane. The prototypical germinant receptor in Bacillus subtilis responds to L-alanine and is thought to be a complex of proteins encoded by the genes in the gerA operon: gerAA , gerAB , and gerAC . The GerAB subunit has recently been shown to function as the nutrient sensor, but beyond contributing to complex stability, no additional functions have been attributed to the other two subunits. Here, we investigate the role of GerAA. We resurrect a previously characterized allele of gerA (termed gerA* ) that carries a mutation in gerAA and show it constitutively activates germination even in the presence of a wild-type copy of gerA . Using an enrichment strategy to screen for suppressors of gerA* , we identified mutations in all three gerA genes that restore a functional receptor. Characterization of two distinct gerAB suppressors revealed that one ( gerAB[E105K]) reduces the GerA complex's ability to respond to L-alanine, while another ( gerAB[F259S] ) disrupts the germinant signal downstream of L-alanine recognition. These data argue against models in which GerAA is directly or indirectly involved in germinant sensing. Rather, our data suggest that GerAA is responsible for transducing the nutrient signal sensed by GerAB. While the steps downstream of gerAA have yet to be uncovered, these results validate the use of a dominant-negative genetic approach in elucidating the gerA signal transduction pathway. Importance Endospore formers are a broad group of bacteria that can enter dormancy upon starvation and exit dormancy upon sensing the return of nutrients. How dormant spores sense and respond to these nutrients is poorly understood. Here, we identify a key step in the signal transduction pathway that is activated after spores detect the amino acid L-alanine. We present a model that provides a more complete picture of this process that is critical for allowing dormant spores to germinate and resume growth.

scholarly journals Genetic evidence for signal transduction within the Bacillus subtilis GerA germinant receptor

2021 ◽  
Author(s):  
Jeremy D. Amon ◽  
Lior Artzi ◽  
David Z. Rudner
Keyword(s):  
Signal Transduction ◽  
Bacillus Subtilis ◽  
Signal Transduction Pathway ◽  
Dominant Negative ◽  
Bacterial Spores ◽  
Wild Type ◽  
Enrichment Strategy ◽  
Functional Receptor

Bacterial spores can rapidly exit dormancy through the process of germination. This process begins with the activation of nutrient receptors embedded in the spore membrane. The prototypical germinant receptor in Bacillus subtilis responds to L-alanine and is thought to be a complex of proteins encoded by the genes in the gerA operon: gerAA, gerAB, and gerAC. The GerAB subunit has recently been shown to function as the nutrient sensor, but beyond contributing to complex stability, no additional functions have been attributed to the other two subunits. Here, we investigate the role of GerAA. We resurrect a previously characterized allele of gerA (termed gerA*) that carries a mutation in gerAA and show it constitutively activates germination even in the presence of a wild-type copy of gerA. Using an enrichment strategy to screen for suppressors of gerA*, we identified mutations in all three gerA genes that restore a functional receptor. Characterization of two distinct gerAB suppressors revealed that one (gerAB-E105K) reduces the GerA complex's ability to respond to L-alanine, while another (gerAB-F259S) disrupts the germinant signal downstream of L-alanine recognition. These data argue against models in which GerAA is directly or indirectly involved in germinant sensing. Rather, our data suggest that GerAA is responsible for transducing the nutrient signal sensed by GerAB. While the steps downstream of gerAA have yet to be uncovered, these results validate the use of a dominant-negative genetic approach in elucidating the gerA signal transduction pathway.

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