scholarly journals The thylakoid membrane protein ALB3 associates with the cpSecY-translocase in Arabidopsis thaliana

2002 ◽  
Vol 368 (3) ◽  
pp. 777-781 ◽  
Author(s):  
Eva KLOSTERMANN ◽  
Imke DROSTE gen. HELLING ◽  
Jean-Pierre CARDE ◽  
Danja SCHÜNEMANN
Keyword(s):  
Arabidopsis Thaliana ◽  
Membrane Protein ◽  
Thylakoid Membrane ◽  
Cytoplasmic Membrane ◽  
Gel Filtration ◽  
Direct Interaction ◽  
Electron Microscopic ◽  
Thylakoid Membrane Proteins ◽  
Oligomeric Complex ◽  
Blue Native

The integration of light-harvesting chlorophyll proteins (LHCPs) into the thylakoid membrane requires the integral thylakoid membrane protein ALB3, a homologue of the bacterial cytoplasmic membrane protein YidC. In bacteria, YidC is associated with the SecY-translocase and facilitates the integration of Sec-dependent proteins into the plasma membrane. In addition, it is also involved in the insertion of Sec-independent proteins. In the present study we demonstrate, in Arabidopsis thaliana, that most ALB3 is a constituent of an oligomeric complex of approx. 180kDa. In addition, we detected ALB3 in several higher-molecular-mass complexes (up to 700kDa). Furthermore, we show that most ALB3 co-fractionates with cpSecY during gel-filtration analysis and blue native gel electrophoresis, suggesting an association of ALB3 with the cpSecY complex. A direct interaction of ALB3 with the cpSecY complex was demonstrated by co-immunoprecipitation experiments using digitonin-solubilized thylakoid membrane proteins and anti-cpSecY or anti-ALB3 antibodies. This result was further confirmed by electron microscopic co-immunolocalization of ALB3 and cpSecY. In addition, an association of ALB3 with the cpSecY complex was demonstrated directly by cross-linking experiments using the chemical cross-linker disuccinimidyl suberate.

Integration of the Thylakoid Membrane Protein Cytochromeb6in the Cytoplasmic Membrane ofEscherichia coli†

Biochemistry ◽  
2005 ◽  
Vol 44 (20) ◽  
pp. 7570-7576 ◽  
Author(s):  
Jaroslaw Króliczewski ◽  
Katarzyna Hombek-Urban ◽  
Andrzej Szczepaniak
Keyword(s):  
Membrane Protein ◽  
Thylakoid Membrane ◽  
Cytoplasmic Membrane ◽  
Ofescherichia Coli

scholarly journals The Zinc-Finger Thylakoid-Membrane Protein FIP Is Involved With Abiotic Stress Response in Arabidopsis thaliana

2018 ◽  
Vol 9 ◽  
Author(s):  
Karina L. Lopes ◽  
Ricardo A. O. Rodrigues ◽  
Marcos C. Silva ◽  
Wiliane G. S. Braga ◽  
Marcio C. Silva-Filho
Keyword(s):  
Arabidopsis Thaliana ◽  
Abiotic Stress ◽  
Stress Response ◽  
Membrane Protein ◽  
Zinc Finger ◽  
Thylakoid Membrane ◽  
Abiotic Stress Response

scholarly journals Direct Interaction of the EpsL and EpsM Proteins of the General Secretion Apparatus in Vibrio cholerae

1999 ◽  
Vol 181 (10) ◽  
pp. 3129-3135 ◽  
Author(s):  
Maria Sandkvist ◽  
Lloyd P. Hough ◽  
Mira M. Bagdasarian ◽  
Michael Bagdasarian
Keyword(s):  
Outer Membrane ◽  
Vibrio Cholerae ◽  
Cytoplasmic Membrane ◽  
Cell Envelope ◽  
Gel Filtration ◽  
Direct Interaction ◽  
Stable Complex ◽  
Extracellular Secretion ◽  
Triton X

ABSTRACT The general secretion pathway of gram-negative bacteria is responsible for extracellular secretion of a number of different proteins, including proteases and toxins. This pathway supports secretion of proteins across the cell envelope in two distinct steps, in which the second step, involving translocation through the outer membrane, is assisted by at least 13 different gene products. Two of these components, the cytoplasmic membrane proteins EpsL and EpsM ofVibrio cholerae, have been purified and characterized. Based on gel filtration analysis, both purified EpsM(His)6 and wild-type EpsL present in anEscherichia coli Triton X-100 extract are dimeric proteins. EpsL and EpsM were also found to interact directly and form a Triton X-100 stable complex that could be precipitated with either anti-EpsL or anti-EpsM antibodies. In addition, when the L and M proteins were coexpressed in E. coli, they formed a stable complex and protected each other from proteolytic degradation, indicating that these two proteins interact in vivo and that no other Eps protein is required for their association. Since EpsL is predicted to contain a large cytoplasmic domain, while EpsM is predominantly exposed on the periplasmic side, we speculate that these components might be part of a structure that is involved in bridging the inner and outer membranes. Furthermore, since EpsL has previously been shown to interact with the autophosphorylating cytoplasmic membrane protein EpsE, we hypothesize that this trimolecular complex might be involved in regulating the opening and closing of the secretion pore and/or transducing energy to the site of outer membrane translocation.

scholarly journals A stromal protein factor maintains the solubility and insertion competence of an imported thylakoid membrane protein.

1991 ◽  
Vol 112 (4) ◽  
pp. 603-613 ◽  
Author(s):  
L A Payan ◽  
K Cline
Keyword(s):  
Membrane Protein ◽  
Thylakoid Membrane ◽  
Gel Filtration ◽  
Chloroplast Envelope ◽  
Membrane Insertion ◽  
Protein Factor ◽  
Stromal Component ◽  
Thylakoid Protein ◽  
Chloroplast Stroma

The light-harvesting chlorophyll a/b protein (LHCP) is an approximately 25,000-D thylakoid membrane protein. LHCP is synthesized in the cytosol as a precursor and must translocate across the chloroplast envelope before becoming integrally associated with the thylakoid bilayer. Previous studies demonstrated that imported LHCP traverses the chloroplast stroma as a soluble intermediate before thylakoid insertion. Here, examination of this intermediate revealed that it is a stable, discrete approximately 120,000-D species and thus either an LHCP oligomer or a complex with another component. In vitro-synthesized LHCP can be converted to a similar form by incubation with a stromal extract. The stromal component responsible for this conversion is proteinaceous as evidenced by its inactivation by heat, protease, and NEM. Furthermore, the conversion activity coelutes from a gel filtration column with a stromal protein factor(s) previously shown to be necessary for LHCP integration into isolated thylakoids. Conversion of LHCP to the 120-kD form prevents aggregation and maintains its competence for thylakoid insertion. However, conversion to this form is apparently not sufficient for membrane insertion because the isolated 120-kD LHCP still requires stroma to complete the integration process. This suggests a need for at least one more stroma-mediated reaction. Our results explain how a hydrophobic thylakoid protein remains soluble as it traverses the aqueous stroma. Moreover, they describe in part the function of the stromal requirement for insertion into the thylakoid membrane.

scholarly journals The Thylakoid Membrane Protein CGL160 Supports CF1CF0 ATP Synthase Accumulation in Arabidopsis thaliana

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0121658 ◽  
Author(s):  
Rikard Fristedt ◽  
Nádia Figueira Martins ◽  
Daniela Strenkert ◽  
Cornelia A. Clarke ◽  
Monika Suchoszek ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Membrane Protein ◽  
Atp Synthase ◽  
Thylakoid Membrane

Molekulargewicht, Größe und Gestalt von Proteinen der Thylakoidmembran / Molecular Weight, Size and Shape of Thylakoid-Membrane Proteins

1971 ◽  
Vol 26 (8) ◽  
pp. 825-831 ◽  
Author(s):  
Wilhelm Menke ◽  
Hans-Georg Ruppel
Keyword(s):  
Molecular Weight ◽  
Formic Acid ◽  
Thylakoid Membrane ◽  
Gel Filtration ◽  
Water Soluble ◽  
Constant Thickness ◽  
Structural Protein ◽  
Lamellar System ◽  
Variable Diameter ◽  
Thylakoid Membrane Proteins

Chloroplasten, Membranproteine, Molekulargewicht, KonformationThe lamellar system of chloroplasts, dissolved in concentrated formic acid, may be freed from lipids by dialysis or gel filtration. The structural protein on both sides of the isoelectric region is water-soluble. The molecular weight was determined to be 470 000 at pH 3.0 - 3.4. Electron micrographs reveal disc-like particles of variable diameter but constant thickness. Particles of 100 Å diameter and 50 Å thickness are mainly observed. The limiting viscosity number [η] = 12 (ml/g) demonstrated that the particles are also anisodiametric in solution. It follows from changes in circular dichroism and infrared absorption that the conformation of the polypeptides is altered by the formic acid treatment. The structural protein can be separated into polypeptides in buffers containing dodecylsulphate, yielding a major component of molecular weight 25 000. From these experiments it may be concluded that one protein layer is contained in the thylakoid membrane which is composed of supra-molecular structural elements.

Immunocytochemical Localization of Amyloid Protein AA in the “Dense Fibrillar Inclusions” of the Reticuloendothelical Cells

1977 ◽  
Vol 35 ◽  
pp. 438-439
Author(s):  
T. Shirahama ◽  
M. Skinner ◽  
A.S. Cohen
Keyword(s):  
Amyloid Fibril ◽  
Close Association ◽  
Gel Filtration ◽  
Fibril Formation ◽  
Amyloid Protein ◽  
Electron Microscopic ◽  
Amyloid Deposits ◽  
Amyloid Fibril Formation ◽  
Electron Microscopic Technique ◽  
Lysosomal System

A1thought the mechanisms of amyloidogenesis have not been entirely clarified, proteolysis of the parent proteins may be one of the important steps in the amyloid fibril formation. Recently, we reported that "dense fibrillar inclusions" (DFI), which had the characteristics of lysosomes and contained organized fibrillar profiles as well, were observed in the reticuloendothelial cells in close association with the foci of new amyloid deposits. We considered the findings as evidence for the involvement of lysosomal system in amyloid fibril formation (l). In the present study, we attempted to determine the identity of the contents of the DFI by the use of antisera against the amyloid protein (AA) and an immuno-electron microscopic technique.Amyloidosis was induced in CBA/J mice by daily injections of casein (l). AA was isolated from amyloid-laden spleens by gel filtration and antibody to it was produced in rabbits (2). For immunocytochemistry, the unlabeled antibody enzyme method (3) was employed.

Electron Microscopic Analysis of Myonecrosis Induced by a Pure Component Isolated From Rattlesnake Venom

1976 ◽  
Vol 34 ◽  
pp. 292-293
Author(s):  
Charlotte L. Ownby ◽  
David Cameron ◽  
Anthony T. Tu
Keyword(s):  
Gel Filtration ◽  
Microscopic Analysis ◽  
The United States ◽  
Exchange Chromatography ◽  
Pure Component ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Mouse Muscle ◽  
Major Health Problem ◽  
Rattlesnake Venom

In the United States the major health problem resulting from snakebite poisoning is local tissue damage, i.e. hemorrhage and myonecrosis. Since commercial antivenin does not usually prevent such damage to tissue, a more effective treatment of snakebite-induced myonecrosis is needed. To aid in the development of such a treatment the pathogenesis of myonecrosis induced by a pure component of rattlesnake venom was studied at the electron microscopic level.The pure component, a small (4,300 mol. wt.), basic (isoelectric point of 9.6) protein, was isolated from crude prairie rattlesnake (Crotalus viridis viridis) venom by gel filtration (Sephadex G-50) followed by cation exchange chromatography (Sephadex C-25), and shown to be pure by electrophoresis. Selection of the myotoxic component was based on light microscopic observations of injected mouse muscle.

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