scholarly journals The Drosophila lethal(2)giant larvae tumor suppressor protein forms homo-oligomers and is associated with nonmuscle myosin II heavy chain.

1994 ◽  
Vol 127 (5) ◽  
pp. 1361-1373 ◽  
Author(s):  
D Strand ◽  
R Jakobs ◽  
G Merdes ◽  
B Neumann ◽  
A Kalmes ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Malignant Tumors ◽  
Myosin Ii ◽  
Protein A ◽  
Gel Filtration ◽  
Nonmuscle Myosin ◽  
Developmental Abnormalities ◽  
Cytoskeletal Network ◽  
Nonmuscle Myosin Ii ◽  
Ring Gland

Inactivation of the Drosophila lethal(2)giant larvae (l(2)gl) gene causes malignant tumors in the brain and the imaginal discs and produces developmental abnormalities in other tissues, including the germline, the ring gland and the salivary glands. Our investigations into the l(2)gl function have revealed that the gene product, or p127 protein, acts as a cytoskeletal protein distributed in both the cytoplasm and on the inner face of lateral cell membranes in a number of tissues throughout development. To determine whether p127 can form oligomers or can stably interact with other proteins we have analyzed the structure of the cytosolic form of p127. Using gel filtration and immunoaffinity chromatography we found that p127 is consistently recovered as high molecular weight complexes that contain predominantly p127 and at least ten additional proteins. Blot overlay assays indicated that p127 can form homo-oligomers and the use of a series of chimaeric proteins made of segments of p127 fused to protein A, which alone behaves as a monomer, showed that p127 contains at least three distinct domains contributing to its homo-oligomerization. Among the proteins separated from the immuno-purified p127 complexes or isolated by virtue of their affinity to p127, we identified one of the proteins by microsequencing as nonmuscle myosin II heavy chain. Further blot overlay assay showed that p127 can directly interact with nonmuscle myosin II. These findings confirm that p127 is a component of a cytoskeletal network including myosin and suggest that the neoplastic transformation resulting from l(2)gl gene inactivation may be caused by the partial disruption of this network.

A serine-kinase associated with the p127-l(2)gl tumour suppressor of Drosophila may regulate the binding of p127 to nonmuscle myosin II heavy chain and the attachment of p127 to the plasma membrane

1996 ◽  
Vol 109 (6) ◽  
pp. 1359-1368 ◽  
Author(s):  
A. Kalmes ◽  
G. Merdes ◽  
B. Neumann ◽  
D. Strand ◽  
B.M. Mechler
Keyword(s):  
Plasma Membrane ◽  
Heavy Chain ◽  
Posttranslational Modifications ◽  
Myosin Ii ◽  
Gel Filtration ◽  
Tumour Suppressor ◽  
Nonmuscle Myosin ◽  
Serine Kinase ◽  
Nonmuscle Myosin Ii

The p127 tumour suppressor protein encoded by the lethal(2)giant larvae, [l(2)gl], gene of Drosophila melanogaster is a component of a cytoskeletal network distributed in both the cytoplasm and on the inner face of the plasma membrane. The p127 protein forms high molecular mass complexes consisting mainly of homo-oligomerized p127 molecules and at least ten additional proteins. One of these proteins has been recently identified as nonmuscle myosin type II heavy chain. To determine the functional interactions between p127 and other proteins present in the p127 complexes, we analyzed p127 for posttranslational modifications and found that p127 can be phosphorylated at serine residues. In this report we describe the characteristics of a serine kinase which is associated with p127, as judged by its recovery in p127 complexes purified by either gel filtration or immuno-affinity chromatography. This kinase phosphorylates p127 in vitro and its activation by supplementing ATP results in the release of p127 from the plasma membrane. Moreover, similar activation of the kinase present in immuno-purified p127 complexes dissociates nonmuscle myosin II from p127 without affecting the homo-oligomerization of p127. This dissociation can be inhibited by staurosporine and a 26mer peptide covering amino acid positions 651 to 676 of p127 and containing five serine residues which are evolutionarily conserved from Drosophila to humans. These results indicate that a serine-kinase tightly associated with p127 regulates p127 binding with components of the cytoskeleton present in both the cytoplasm and on the plasma membrane.

scholarly journals Two Regions of the Tail Are Necessary for the Isoform-specific Functions of Nonmuscle Myosin IIB

2007 ◽  
Vol 18 (3) ◽  
pp. 1009-1017 ◽  
Author(s):  
Masaaki K. Sato ◽  
Masayuki Takahashi ◽  
Michio Yazawa
Keyword(s):  
Heavy Chain ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Recognition Sites ◽  
Self Recognition ◽  
Nonmuscle Myosin Ii ◽  
Exogenous Expression ◽  
Mhc Iib ◽  
C 63

To function in the cell, nonmuscle myosin II molecules assemble into filaments through their C-terminal tails. Because myosin II isoforms most likely assemble into homo-filaments in vivo, it seems that some self-recognition mechanisms of individual myosin II isoforms should exist. Exogenous expression of myosin IIB rod fragment is thus expected to prevent the function of myosin IIB specifically. We expected to reveal some self-recognition sites of myosin IIB from the phenotype by expressing appropriate myosin IIB rod fragments. We expressed the C-terminal 305-residue rod fragment of the myosin IIB heavy chain (BRF305) in MRC-5 SV1 TG1 cells. As a result, unstable morphology was observed like MHC-IIB−/− fibroblasts. This phenotype was not observed in cells expressing BRF305 mutants: 1) with a defect in assembling, 2) lacking N-terminal 57 residues (N-57), or 3) lacking C-terminal 63 residues (C-63). A myosin IIA rod fragment ARF296 corresponding to BRF305 was not effective. However, the chimeric ARF296, in which the N-57 and C-63 of BRF305 were substituted for the corresponding regions of ARF296, acquired the ability to induce unstable morphology. We propose that the N-57 and C-63 of BRF305 are involved in self-recognition when myosin IIB molecules assemble into homo-filament.

TFEC Can Function as a Transcriptional Activator of the Nonmuscle Myosin II Heavy Chain-A Gene in Transfected Cells

Biochemistry ◽  
2001 ◽  
Vol 40 (30) ◽  
pp. 8887-8897 ◽  
Author(s):  
Myung-Chul Chung ◽  
Hyung-Kwoun Kim ◽  
Sachiyo Kawamoto
Keyword(s):  
Heavy Chain ◽  
Myosin Ii ◽  
Transcriptional Activator ◽  
Nonmuscle Myosin ◽  
Transfected Cells ◽  
Nonmuscle Myosin Ii

Structural abnormalities develop in the brain after ablation of the gene encoding nonmuscle myosin II-B heavy chain

2001 ◽  
Vol 433 (1) ◽  
pp. 62-74 ◽  
Author(s):  
Antonella N. Tullio ◽  
Paul C. Bridgman ◽  
Nancy J. Tresser ◽  
Chi-Chao Chan ◽  
Mary Anne Conti ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Gene Encoding ◽  
Nonmuscle Myosin Ii ◽  
Structural Abnormalities ◽  
The Brain

Association of theDrosophila lethal(2) giant larvae, l(2)gl, tumour suppressor protein, p127, with nonmuscle myosin II heavy chain

1995 ◽  
Vol 121 (S1) ◽  
pp. A67-A67
Author(s):  
Gunter Merdes ◽  
Rainer Jakobs ◽  
Beate Neumann ◽  
Zuo Wei Su ◽  
Daniel P. Kiehart ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Myosin Ii ◽  
Tumour Suppressor ◽  
Nonmuscle Myosin ◽  
Tumour Suppressor Protein ◽  
Nonmuscle Myosin Ii

scholarly journals Menin, a tumor suppressor, associates with nonmuscle myosin II-A heavy chain

Oncogene ◽  
2003 ◽  
Vol 22 (41) ◽  
pp. 6347-6358 ◽  
Author(s):  
Victor H Obungu ◽  
A Lee Burns ◽  
Sunita K Agarwal ◽  
Settara C Chandrasekharapa ◽  
Robert S Adelstein ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Heavy Chain ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii

scholarly journals Myosin II is associated with Golgi membranes: identification of p200 as nonmuscle myosin II on Golgi-derived vesicles

1997 ◽  
Vol 110 (18) ◽  
pp. 2155-2164 ◽  
Author(s):  
E. Ikonen ◽  
J.B. de Almeid ◽  
K.R. Fath ◽  
D.R. Burgess ◽  
K. Ashman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heavy Chain ◽  
Cultured Cells ◽  
Sequence Data ◽  
Myosin Ii ◽  
Light And Electron Microscopy ◽  
Actin Binding ◽  
Nonmuscle Myosin ◽  
Golgi Membranes ◽  
Nonmuscle Myosin Ii

A variety of peripheral membrane proteins associate dynamically with Golgi membranes during the budding and trafficking of transport vesicles in eukaryotic cells. A monoclonal antibody (AD7) raised against Golgi membranes recognizes a peripheral membrane protein, p200, which associates with vesicles budding off the trans-Golgi network (TGN). Based on preliminary findings, a potential association between p200 and myosin on Golgi membranes was investigated. Immunofluorescence staining of cultured cells under a variety of fixation conditions was carried out using an antibody raised against chick brush border nonmuscle myosin II. We show that, in addition to being found in the cytoplasm or associated with stress fibres, nonmuscle myosin II is also specifically localized on Golgi membranes. Myosin II was also detected on Golgi membranes by immunoblotting and by immunogold labeling at the electron microscopy level where it was found to be concentrated on Golgi-derived vesicles. The association of myosin II with Golgi membranes is dynamic and was found to be enhanced following activation of G proteins. Myosin II staining of Golgi membranes was also disrupted by brefeldin A (BFA). Colocalization of the AD7 and myosin II antibodies at the light and electron microscopy levels led us to investigate the nature of the 200 kDa protein recognized by both antibodies. The 200 kDa protein immunoprecipiated by the AD7 antibody was isolated from MDCK cells and used for microsequencing. Amino acid sequence data enabled us to identify p200 as the heavy chain of nonmuscle myosin IIA. In addition, an extra protein (240 kDa) recognized by the AD7 antibody specifically in extracts of HeLa cells, was sequenced and identified as another actin-binding protein, filamin. These results show that nonmuscle myosin II is associated with Golgi membranes and that the vesicle-associated protein p200, is itself a heavy chain of myosin II.

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