scholarly journals A pathway for cell wall anchorage of Saccharomyces cerevisiae alpha-agglutinin.

1994 ◽  
Vol 14 (7) ◽  
pp. 4825-4833 ◽  
Author(s):  
C F Lu ◽  
J Kurjan ◽  
P N Lipke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Soluble Form ◽  
Gpi Anchor ◽  
Glycosyl Phosphatidylinositol ◽  
Experimental Support ◽  
Cell Biol ◽  
A Cell

Saccharomyces cerevisiae alpha-agglutinin is a cell wall-anchored adhesion glycoprotein. The previously identified 140-kDa form, which contains a glycosyl-phosphatidylinositol (GPI) anchor (D. Wojciechowicz, C.-F. Lu, J. Kurjan, and P. N. Lipke, Mol. Cell. Biol. 13:2554-2563, 1993), and additional forms of 80, 150, 250 to 300, and > 300 kDa had the properties of intermediates in a transport and cell wall anchorage pathway. N glycosylation and additional modifications resulted in successive increases in size during transport. The 150- and 250- to 300-kDa forms were membrane associated and are likely to be intermediates between the 140-kDa form and a cell surface GPI-anchored form of > 300 kDa. A soluble form of > 300 kDa that lacked the GPI anchor had properties of a periplasmic intermediate between the plasma membrane form and the > 300-kDa cell wall-anchored form. These results constitute experimental support for the hypothesis that GPI anchors act to localize alpha-agglutinin to the plasma membrane and that cell wall anchorage involves release from the GPI anchor to produce a periplasmic intermediate followed by linkage to the cell wall.

A pathway for cell wall anchorage of Saccharomyces cerevisiae alpha-agglutinin

1994 ◽  
Vol 14 (7) ◽  
pp. 4825-4833
Author(s):  
C F Lu ◽  
J Kurjan ◽  
P N Lipke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Soluble Form ◽  
Gpi Anchor ◽  
Glycosyl Phosphatidylinositol ◽  
Experimental Support ◽  
Cell Biol ◽  
A Cell

Saccharomyces cerevisiae alpha-agglutinin is a cell wall-anchored adhesion glycoprotein. The previously identified 140-kDa form, which contains a glycosyl-phosphatidylinositol (GPI) anchor (D. Wojciechowicz, C.-F. Lu, J. Kurjan, and P. N. Lipke, Mol. Cell. Biol. 13:2554-2563, 1993), and additional forms of 80, 150, 250 to 300, and > 300 kDa had the properties of intermediates in a transport and cell wall anchorage pathway. N glycosylation and additional modifications resulted in successive increases in size during transport. The 150- and 250- to 300-kDa forms were membrane associated and are likely to be intermediates between the 140-kDa form and a cell surface GPI-anchored form of > 300 kDa. A soluble form of > 300 kDa that lacked the GPI anchor had properties of a periplasmic intermediate between the plasma membrane form and the > 300-kDa cell wall-anchored form. These results constitute experimental support for the hypothesis that GPI anchors act to localize alpha-agglutinin to the plasma membrane and that cell wall anchorage involves release from the GPI anchor to produce a periplasmic intermediate followed by linkage to the cell wall.

scholarly journals Glycosyl phosphatidylinositol-dependent cross-linking of alpha-agglutinin and beta 1,6-glucan in the Saccharomyces cerevisiae cell wall.

1995 ◽  
Vol 128 (3) ◽  
pp. 333-340 ◽  
Author(s):  
C F Lu ◽  
R C Montijn ◽  
J L Brown ◽  
F Klis ◽  
J Kurjan ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Secretory Pathway ◽  
Molecular Size ◽  
Cross Linking ◽  
Cell Contact ◽  
Gpi Anchor ◽  
Adhesion Protein ◽  
Glycosyl Phosphatidylinositol ◽  
Cross Linkage

The cell adhesion protein alpha-agglutinin is bound to the outer surface of the Saccharomyces cerevisiae cell wall and mediates cell-cell contact in mating. alpha-Agglutinin is modified by addition of a glycosyl phosphatidylinositol (GPI) anchor as it traverses the secretory pathway. The presence of a GPI anchor is essential for cross-linking into the wall, but the fatty acid and inositol components of the anchor are lost before cell wall association (Lu, C.-F., J. Kurjan, and P. N. Lipke, 1994. A pathway for cell wall anchorage of Saccharomyces cerevisiae alpha-agglutinin. Mol. Cell. Biol. 14:4825-4833). Cell wall association of alpha-agglutinin was accompanied by an increase in size and a gain in reactivity to antibodies directed against beta 1,6-glucan. Several kre mutants, which have defects in synthesis of cell wall beta 1,6-glucan, had reduced molecular size of cell wall alpha-agglutinin. These findings demonstrate that the cell wall form of alpha-agglutinin is covalently associated with beta 1,6-glucan. The alpha-agglutinin biosynthetic precursors did not react with antibody to beta 1,6-glucan, and the sizes of these forms were unaffected in kre mutants. A COOH-terminal truncated form of alpha-agglutinin, which is not GPI anchored and is secreted into the medium, did not react with the anti-beta 1,6-glucan. We propose that extracellular cross-linkage to beta 1,6-glucan mediates covalent association of alpha-agglutinin with the cell wall in a manner that is dependent on prior addition of a GPI anchor to alpha-agglutinin.

Processing of Hemojuvelin Requires Retrograde Trafficking to the Golgi in HepG2 Cells.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3845-3845
Author(s):  
An-Sheng Zhang ◽  
Julia Julia Maxson ◽  
Caroline A Enns
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Hepg2 Cells ◽  
Iron Homeostasis ◽  
Bmp Signaling ◽  
Soluble Form ◽  
Gpi Anchor ◽  
Retrograde Trafficking ◽  
Hepcidin Expression ◽  
Bone Morphogenic Proteins

Abstract Hemojuvelin (HJV) was recently identified as a critical regulator of iron homeostasis. It is either associated with the cells through a GPI-anchor or released as a soluble form. The cellular form acts as a co-receptor for bone morphogenic proteins (BMPs) and activates the transcription of hepcidin, a hormone that regulates iron efflux from cells. Soluble HJV antagonizes BMP signaling and suppresses hepcidin expression. Secretion of HJV requires binding to the transmembrane receptor neogenin. In this study we examined the trafficking and processing of HJV. Cellular HJV reached the plasma membrane without obtaining complex oligosaccharides, indicating that HJV avoided Golgi processing. Secreted HJV, in contrast, had complex oligosaccharides and could be derived from the pool of HJV at the plasma membrane. Neogenin did not play a role in HJV trafficking to the cell surface but was necessary for secretion of HJV, suggesting that it could be involved in either retrograde trafficking of HJV or in cleavage leading to secretion.

scholarly journals Lack of GTP-bound Rho1p in secretory vesicles of Saccharomyces cerevisiae

2003 ◽  
Vol 162 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Mitsuhiro Abe ◽  
Hiroshi Qadota ◽  
Aiko Hirata ◽  
Yoshikazu Ohya
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Vesicular Transport ◽  
Secretory Vesicles ◽  
Glucan Synthase ◽  
Exchange Factor ◽  
Inactive Form ◽  
A Cell

Rho1p, an essential Rho-type GTPase in Saccharomyces cerevisiae, activates its effectors in the GTP-bound form. Here, we show that Rho1p in secretory vesicles cannot activate 1,3-β-glucan synthase, a cell wall synthesizing enzyme, during vesicular transport to the plasma membrane. Analyses with an antibody preferentially reacting with the GTP-bound form of Rho1p revealed that Rho1p remains in the inactive form in secretory vesicles. Rom2p, the GDP/GTP exchange factor of Rho1p, is preferentially localized on the plasma membrane even when vesicular transport is blocked. Overexpression of Rom2p results in delocalization of Rom2p and accumulation of 1,3-β-glucan in secretory vesicles. Based on these results, we propose that Rho1p is kept inactive in intracellular secretory organelles, resulting in repression of the activity of the cell wall–synthesizing enzyme within cells.

scholarly journals Glucose-induced sequential processing of a glycosyl-phosphatidylinositol-anchored ectoprotein in Saccharomyces cerevisiae.

1996 ◽  
Vol 16 (1) ◽  
pp. 442-456 ◽  
Author(s):  
G Müller ◽  
E Gross ◽  
S Wied ◽  
W Bandlow
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Glycosyl Phosphatidylinositol ◽  
Sequential Processing ◽  
Protein Label ◽  
Covalently Linked

Transfer of spheroplasts from the yeast Saccharomyces cerevisiae to glucose leads to the activation of an endogenous (glycosyl)-phosphatidylinositol-specific phospholipase C ([G]PI-PLC), which cleaves the anchor of at least one glycosyl-phosphatidylinositol (GPI)-anchored protein, the cyclic AMP (cAMP)-binding ectoprotein Gce1p (G. Müller and W. Bandlow, J. Cell Biol. 122:325-336, 1993). Analyses of the turnover of two constituents of the anchor, myo-inositol and ethanolamine, relative to the protein label as well as separation of the two differently processed versions of Gce1p by isoelectric focusing in spheroplasts demonstrate the glucose-induced conversion of amphiphilic Gce1p first into a lipolytically cleaved hydrophilic intermediate, which is then processed into another hydrophilic version lacking both myo-inositol and ethanolamine. When incubated with unlabeled spheroplasts, the lipolytically cleaved intermediate prepared in vitro is converted into the version lacking all anchor constituents, whereby the anchor glycan is apparently removed as a whole. The secondary cleavage ensues independently of the carbon source, attributing the key role in glucose-induced anchor processing to the endogenous (G)PI-PLC. The secondary processing of the lipolytically cleaved intermediate of Gce1p at the plasma membrane is correlated with the emergence of a covalently linked high-molecular-weight form of a cAMP-binding protein at the cell wall. This protein lacks anchor components, and its protein moiety appears to be identical with double-processed Gce1p detectable at the plasma membrane in spheroplasts. The data suggest that glucose-induced double processing of GPI anchors represents part of a mechanism of regulated cell wall expression of proteins in yeast cells.

scholarly journals Comparative Roles of the Cell Wall and Cell Membrane in Limiting Uptake of Xenobiotic Molecules by Saccharomyces cerevisiae

2003 ◽  
Vol 47 (6) ◽  
pp. 2012-2014 ◽  
Author(s):  
Mustapha Aouida ◽  
Omar Tounekti ◽  
Omrane Belhadj ◽  
Lluis M. Mir
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Protein

ABSTRACT Using reversible electropermeabilization of cells and spheroplasts, we show that the cell wall and plasma membrane partly account for bleomycin resistance by acting as two independent barriers. We also report on the presence of a membrane protein that may be responsible for bleomycin internalization and toxicity in Saccharomyces cerevisiae.

scholarly journals The AWA1 Gene Is Required for the Foam-Forming Phenotype and Cell Surface Hydrophobicity of Sake Yeast

2002 ◽  
Vol 68 (4) ◽  
pp. 2018-2025 ◽  
Author(s):  
Hitoshi Shimoi ◽  
Kazutoshi Sakamoto ◽  
Masaki Okuda ◽  
Ratchanee Atthi ◽  
Kazuhiro Iwashita ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Repetitive Sequences ◽  
Alcoholic Beverage ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
A Cell ◽  
Characteristic Sequences ◽  
Foam Forming ◽  
Almost All

ABSTRACT Sake, a traditional alcoholic beverage in Japan, is brewed with sake yeasts, which are classified as Saccharomyces cerevisiae. Almost all sake yeasts form a thick foam layer on sake mash during the fermentation process because of their cell surface hydrophobicity, which increases the cells' affinity for bubbles. To reduce the amount of foam, nonfoaming mutants were bred from foaming sake yeasts. Nonfoaming mutants have hydrophilic cell surfaces and no affinity for bubbles. We have cloned a gene from a foam-forming sake yeast that confers foaming ability to a nonfoaming mutant. This gene was named AWA1 and structures of the gene and its product were analyzed. The N- and C-terminal regions of Awa1p have the characteristic sequences of a glycosylphosphatidylinositol anchor protein. The entire protein is rich in serine and threonine residues and has a lot of repetitive sequences. These results suggest that Awa1p is localized in the cell wall. This was confirmed by immunofluorescence microscopy and Western blotting analysis using hemagglutinin-tagged Awa1p. Moreover, an awa1 disruptant of sake yeast was hydrophilic and showed a nonfoaming phenotype in sake mash. We conclude that Awa1p is a cell wall protein and is required for the foam-forming phenotype and the cell surface hydrophobicity of sake yeast.

scholarly journals Tetherin is an exosomal tether

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
James R Edgar ◽  
Paul T Manna ◽  
Shinichi Nishimura ◽  
George Banting ◽  
Margaret S Robinson
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Short Range ◽  
Wild Type ◽  
Concomitant Increase ◽  
Gpi Anchor ◽  
Fold Reduction ◽  
Cell Metastasis ◽  
Health And Disease ◽  
Prion Transmission

Exosomes are extracellular vesicles that are released when endosomes fuse with the plasma membrane. They have been implicated in various functions in both health and disease, including intercellular communication, antigen presentation, prion transmission, and tumour cell metastasis. Here we show that inactivating the vacuolar ATPase in HeLa cells causes a dramatic increase in the production of exosomes, which display endocytosed tracers, cholesterol, and CD63. The exosomes remain clustered on the cell surface, similar to retroviruses, which are attached to the plasma membrane by tetherin. To determine whether tetherin also attaches exosomes, we knocked it out and found a 4-fold reduction in plasma membrane-associated exosomes, with a concomitant increase in exosomes discharged into the medium. This phenotype could be rescued by wild-type tetherin but not tetherin lacking its GPI anchor. We propose that tetherin may play a key role in exosome fate, determining whether they participate in long-range or short-range interactions.

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