scholarly journals Protein phosphorylation in intact cultured sycamore (Acer pseudoplatanus) cells and its response to fusicoccin

1986 ◽  
Vol 235 (1) ◽  
pp. 45-48 ◽  
Author(s):  
L Tognoli ◽  
R Colombo
Keyword(s):  
Protein Phosphorylation ◽  
Molecular Mass ◽  
Cultured Cells ◽  
Higher Plants ◽  
Acer Pseudoplatanus ◽  
Cell Fractionation ◽  
Soluble Fractions

Fusicoccin (FC), a natural diterpene glucoside able to stimulate electrogenic H+ extrusion in higher plants, has been shown to stimulate the phosphorylation of a polypeptide of molecular mass approx. 33 kDa in intact cultured cells of sycamore (Acer pseudoplatanus). The effect is specific, rapid and insensitive to cycloheximide. The presence of the 33 kDa polypeptide and the stimulation by FC have been observed in SDS-containing cell homogenates and in the microsomal and soluble fractions after cell fractionation.

scholarly journals Possible Role of Peroxynitrite in the Responses Induced by Fusicoccin in Plant Cultured Cells

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 182 ◽  
Author(s):  
Massimo Malerba ◽  
Raffaella Cerana
Keyword(s):  
Cytochrome C ◽  
Dna Fragmentation ◽  
Stress Responses ◽  
Molecular Chaperones ◽  
Caspase 3 ◽  
Cultured Cells ◽  
Acer Pseudoplatanus ◽  
Cytochrome C Release ◽  
Induced Stress

Fusicoccin (FC) is a well-known phytotoxin able to induce in Acer pseudoplatanus L. (sycamore) cultured cells, a set of responses similar to those induced by stress conditions. In this work, the possible involvement of peroxynitrite (ONOO−) in FC-induced stress responses was studied measuring both in the presence and in the absence of 2,6,8-trihydroxypurine (urate), a specific ONOO− scavenger: (1) cell death; (2) specific DNA fragmentation; (3) lipid peroxidation; (4) production of RNS and ROS; (5) activity of caspase-3-like proteases; and (6) release of cytochrome c from mitochondria, variations in the levels of molecular chaperones Hsp90 in the mitochondria and Hsp70 BiP in the endoplasmic reticulum (ER), and of regulatory 14-3-3 proteins in the cytosol. The obtained results indicate a role for ONOO− in the FC-induced responses. In particular, ONOO− seems involved in a PCD form showing apoptotic features such as specific DNA fragmentation, caspase-3-like protease activity, and cytochrome c release from mitochondria.

Towards a molecular description of cell transformation by avian sarcoma virus

1980 ◽  
Vol 210 (1180) ◽  
pp. 387-396 ◽  
Keyword(s):  
Protein Kinase ◽  
Protein Phosphorylation ◽  
Molecular Mass ◽  
Cellular Protein ◽  
Transformed Cells ◽  
Relative Molecular Mass ◽  
Protein Kinase Activity ◽  
Avian Sarcoma Virus ◽  
Sarcoma Virus ◽  
Avian Sarcoma

The avian sarcoma virus transforming gene product has been identified and partially purified from extracts of transformed cells. It is a phosphoprotein with a relative molecular mass of 60 000 (pp60 src ) with two major sites of phosphorylation. pp60 src appears to be a cyclic-AMP-independent protein kinase as judged by protein phosphorylation with partly purified fractions. The specificity of the phosphorylation observed was judged by inhibition with anti-pp60 src IgG but not by normal IgG and by the fact that the protein kinase activity isolated from ts transformation-mutant infected cells was more thermolabile than that from wild-type transformed cells, thus showing more directly the origin of the enzymic activity. A cellular protein substrate of pp60 src has been identified as a 34000 molecular mass protein. These data together suggest that protein phosphorylation by pp60 src may be a function of the molecule that plays a major role in transformation.

scholarly journals Isolation and characterization of PEP5, a gene essential for vacuolar biogenesis in Saccharomyces cerevisiae.

Genetics ◽  
1990 ◽  
Vol 125 (4) ◽  
pp. 739-752 ◽  
Author(s):  
C A Woolford ◽  
C K Dixon ◽  
M F Manolson ◽  
R Wright ◽  
E W Jones
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Mass ◽  
Open Reading Frame ◽  
Relative Molecular Mass ◽  
Cell Fractionation ◽  
Calculated Molecular Mass ◽  
Reading Frame ◽  
Dna Library ◽  
Isolation And Characterization ◽  
Genomic Dna Library

Abstract pep5 mutants of Saccharomyces cerevisiae accumulate inactive precursors to the vacuolar hydrolases. The PEP5 gene was isolated from a genomic DNA library by complementation of the pep5-8 mutation. Deletion analysis localized the complementing activity to a 3.3-kb DNA fragment. DNA sequence analysis of the PEP5 gene revealed an open reading frame of 1029 codons with a calculated molecular mass for the encoded protein of 117,403 D. Deletion/disruption of the PEP5 gene did not kill the cells. The resulting strains grow very slowly at 37 degrees. The disruption mutant showed greatly decreased activities of all vacuolar hydrolases examined, including PrA, PrB, CpY, and the repressible alkaline phosphatase. Apparently normal precursors forms of the proteases accumulated in pep5 mutants, as did novel forms of PrB antigen. Antibodies raised to a fusion protein that contained almost half of the PEP5 open reading frame allowed detection by immunoblot of a protein of relative molecular mass 107 kD in extracts prepared from wild-type cells. Cell fractionation showed the PEP5 gene product is enriched in the vacuolar fraction and appears to be a peripheral vacuolar membrane protein.

scholarly journals Pantophysin is a ubiquitously expressed synaptophysin homologue and defines constitutive transport vesicles.

1996 ◽  
Vol 134 (3) ◽  
pp. 731-746 ◽  
Author(s):  
N K Haass ◽  
M A Kartenbeck ◽  
R E Leube
Keyword(s):  
Epithelial Cells ◽  
Cultured Cells ◽  
Cell Types ◽  
Human Pancreas ◽  
Cell Fractionation ◽  
Vesicle Membrane ◽  
Cytoplasmic Transport ◽  
Transport Vesicles ◽  
Mrna And Protein Expression ◽  
Exon Structure

Certain properties of the highly specialized synaptic transmitter vesicles are shared by constitutively occurring vesicles. We and others have thus identified a cDNA in various nonneuroendocrine cell types of rat and human that is related to synaptophysin, one of the major synaptic vesicle membrane proteins, which we termed pantophysin. Here we characterize the gene structure, mRNA and protein expression, and intracellular distribution of pantophysin. Its mRNA is detected in murine cell types of nonneuroendocrine as well as of neuroendocrine origin. The intron/exon structure of the murine pantophysin gene is identical to that of synaptophysin except for the last intron that is absent in pantophysin. The encoded polypeptide of calculated mol wt 28,926 shares many sequence features with synaptophysin, most notably the four hydrophobic putative transmembrane domains, although the cytoplasmic end domains are completely different. Using antibodies against the unique carboxy terminus pantophysin can be detected by immunofluorescence microscopy in both exocrine and endocrine cells of human pancreas, and in cultured cells, colocalizing with constitutive secretory and endocytotic vesicle markers in nonneuroendocrine cells and with synaptophysin in cDNA-transfected epithelial cells. By immunoelectron microscopy, the majority of pantophysin reactivity is detected at vesicles with a diameter of < 100 nm that have a smooth surface and an electron-translucent interior. Using cell fractionation in combination with immunoisolation, these vesicles are enriched in a light fraction and shown to contain the cellular vSNARE cellubrevin and the ubiquitous SCAMPs in epithelial cells and synaptophysin in neuroendocrine or cDNA-transfected nonneuroendocrine cells and neuroendocrine tissues. Pantophysin is therefore a broadly distributed marker of small cytoplasmic transport vesicles independent of their content.

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