scholarly journals Manganese toxicity and Saccharomyces cerevisiae Mam3p, a member of the ACDP (ancient conserved domain protein) family

2005 ◽  
Vol 386 (3) ◽  
pp. 479-487 ◽  
Author(s):  
Mei YANG ◽  
Laran T. JENSEN ◽  
Allison J. GARDNER ◽  
Valeria C. CULOTTA

Manganese is an essential, but potentially toxic, trace metal in biological systems. Overexposure to manganese is known to cause neurological deficits in humans, but the pathways that lead to manganese toxicity are largely unknown. We have employed the bakers' yeast Saccharomyces cerevisiae as a model system to identify genes that contribute to manganese-related damage. In a genetic screen for yeast manganese-resistance mutants, we identified S. cerevisiae MAM3 as a gene which, when deleted, would increase cellular tolerance to toxic levels of manganese and also increased the cell's resistance towards cobalt and zinc. By sequence analysis, Mam3p shares strong similarity with the mammalian ACDP (ancient conserved domain protein) family of polypeptides. Mutations in human ACDP1 have been associated with urofacial (Ochoa) syndrome. However, the functions of eukaryotic ACDPs remain unknown. We show here that S. cerevisiae MAM3 encodes an integral membrane protein of the yeast vacuole whose expression levels directly correlate with the degree of manganese toxicity. Surprisingly, Mam3p contributes to manganese toxicity without any obvious changes in vacuolar accumulation of metals. Furthermore, through genetic epistasis studies, we demonstrate that MAM3 operates independently of the well-established manganese-trafficking pathways in yeast, involving the manganese transporters Pmr1p, Smf2p and Pho84p. This is the first report of a eukaryotic ACDP family protein involved in metal homoeostasis.

2016 ◽  
Vol 44 (2) ◽  
pp. 474-478 ◽  
Author(s):  
Chris MacDonald ◽  
Robert C. Piper

Sorting internalized proteins and lipids back to the cell surface controls the supply of molecules throughout the cell and regulates integral membrane protein activity at the surface. One central process in mammalian cells is the transit of cargo from endosomes back to the plasma membrane (PM) directly, along a route that bypasses retrograde movement to the Golgi. Despite recognition of this pathway for decades we are only beginning to understand the machinery controlling this overall process. The budding yeast Saccharomyces cerevisiae, a stalwart genetic system, has been routinely used to identify fundamental proteins and their modes of action in conserved trafficking pathways. However, the study of cell surface recycling from endosomes in yeast is hampered by difficulties that obscure visualization of the pathway. Here we briefly discuss how recycling is likely a more prevalent process in yeast than is widely appreciated and how tools might be built to better study the pathway.


2011 ◽  
Vol 22 (10) ◽  
pp. 1727-1738 ◽  
Author(s):  
Robert J. Tower ◽  
Andrei Fagarasanu ◽  
John D. Aitchison ◽  
Richard A. Rachubinski

Peroxisomes are ubiquitous organelles involved in diverse metabolic processes, most notably the metabolism of lipids and the detoxification of reactive oxygen species. Peroxisomes are highly dynamic and change in size and number in response to both intra- and extracellular cues. In the yeast Saccharomyces cerevisiae, peroxisome growth and division are controlled by both the differential import of soluble matrix proteins and a specialized divisional machinery that includes peroxisome-specific factors, such as members of the Pex11 protein family, and general organelle divisional factors, such as the dynamin-related protein Vps1p. Global yeast two-hybrid analyses have demonstrated interactions between the product of the S. cerevisiae gene of unknown function, YCL056c, and Pex proteins involved in peroxisome biogenesis. Here we show that the protein encoded by YCL056c, renamed Pex34p, is a peroxisomal integral membrane protein that acts independently and also in concert with the Pex11 protein family members Pex11p, Pex25p, and Pex27p to control the peroxisome populations of cells under conditions of both peroxisome proliferation and constitutive peroxisome division. Yeast two-hybrid analysis showed that Pex34p interacts physically with itself and with Pex11p, Pex25p, and Pex27p but not with Vps1p. Pex34p can act as a positive effector of peroxisome division as its overexpression leads to increased numbers of peroxisomes in wild type and pex34Δ cells. Pex34p requires the Pex11 family proteins to promote peroxisome division. Our discovery of Pex34p as a protein involved in the already complex control of peroxisome populations emphasizes the necessity of cells to strictly regulate their peroxisome populations to be able to respond appropriately to changing environmental conditions.


1990 ◽  
Vol 10 (6) ◽  
pp. 2916-2923 ◽  
Author(s):  
D I Chasman ◽  
R D Kornberg

Expression of the yeast Saccharomyces cerevisiae GAL4 protein under its own (galactose-inducible) control gave 5 to 10 times the level of protein observed when the GAL4 gene was on a high-copy plasmid. Purification of GAL4 by a procedure including affinity chromatography on a GAL4-binding DNA column yielded not only GAL4 but also a second protein, shown to be GAL80 by its reaction with an antipeptide antibody. Sequence comparisons of GAL4 and other members of a family of proteins sharing homologous cysteine finger motifs identified an additional region of homology in the middle of these proteins shown by genetic analysis to be important for GAL4 function. GAL4 could be cleaved proteolytically at the boundary of the conserved region, defining internal and carboxy-terminal folded domains.


1990 ◽  
Vol 10 (6) ◽  
pp. 2916-2923
Author(s):  
D I Chasman ◽  
R D Kornberg

Expression of the yeast Saccharomyces cerevisiae GAL4 protein under its own (galactose-inducible) control gave 5 to 10 times the level of protein observed when the GAL4 gene was on a high-copy plasmid. Purification of GAL4 by a procedure including affinity chromatography on a GAL4-binding DNA column yielded not only GAL4 but also a second protein, shown to be GAL80 by its reaction with an antipeptide antibody. Sequence comparisons of GAL4 and other members of a family of proteins sharing homologous cysteine finger motifs identified an additional region of homology in the middle of these proteins shown by genetic analysis to be important for GAL4 function. GAL4 could be cleaved proteolytically at the boundary of the conserved region, defining internal and carboxy-terminal folded domains.


2016 ◽  
Vol 13 (1) ◽  
pp. 93
Author(s):  
Titin Yulinery ◽  
Ratih M.Dewi

Tes kemampuan adalah salah satu kegiatan penting dalam pengendalian mutu dan jaminan kualitas mikrobiologi laboratorium untuk mengukur kompetensi analis dan analisis uji profisiensi membutuhkan persiapan Model mikroorganisme adalah kualitas standar dan validitas. Mikrobiologi uji kualitas produk kedelai utama diarahkan pada kehadiran Saccharomyces cerevisiae ragi (S. cerevisiae), S. Bailli, S. rouxii dankontaminan bakteri seperti Bacillus dan Deinococcus. Jenis ragi dan bakteri yang terlibat dalam proses dan dapat menjadi salah satu parameter kualitas penting dalam persiapan yang dihasilkan. Jumlah dan viabilitas bakteri dan ragi menjadi parameter utama dalam proses persiapan bahan uji. Jumlah tersebut adalah jumlah minimum yang berlaku dapat dianalisis. Jumlah ini harus dibawah 10 CFU diperlukan untuk menunjukkan tingkat hygienitas proses dan tingkat minimal kontaminasi. Viabilitas bakteri dan bahan tes ragi persiapan untuk tes kemahiran kecap yang diawetkan dengan L-pengeringan adalah teknik Deinococcus radiodurans (D. radiodurans) 16 tahun, 58 tahun S. cerevisiae, dan S. roxii 13 tahun. kata kunci: Viabilitas, Deinococcus, khamir, L-pengeringan, Proficiency AbstractProficiency test is one of the important activities in quality control and quality assurance microbiology laboratory for measuring the competence of analysts and analysis Proficiency test requires a model microorganism preparations are standardized quality and validity. Microbiological test of the quality of the main soy products aimed at thepresence of yeast Saccharomyces cerevisiae (S. cerevisiae), S. bailli, S. rouxii and bacterial contaminants such as Bacillus and Deinococcus. Types of yeasts and bacteria involved in the process and can be one of the important quality parameters in the preparation produced. The number and viability of bacteria and yeasts become themain parameters in the process of test preparation materials. The amount in question is the minimum number that is valid can be analyzed. This amount must be below 10 CFU required to indicate the level of hygienitas process and the minimum level of contamination. Viability of bacteria and yeast test preparation materials for proficiencytest of soy sauce that preserved by L-drying technique is Deinococcus radiodurans ( D. radiodurans ) 16 years, 58 years S. cerevisiae, and S. roxii 13 years. key words : Viability, Deinococcus, Khamir, L-drying, Proficiency


Tsitologiya ◽  
2018 ◽  
Vol 60 (7) ◽  
pp. 555-557 ◽  
Author(s):  
E. A. Alekseeva ◽  
◽  
T. A. Evstyukhina ◽  
V. T. Peshekhonov ◽  
V. G. Korolev ◽  
...  

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