A5086302132- Endoplasmic Reticulum Stress and Disease
- Cellular transport and secretion
- Fungal and yeast genetics research
- Autophagy in Disease and Therapy
- Photosynthetic Processes and Mechanisms
- Mitochondrial Function and Pathology
- ATP Synthase and ATPases Research
- Microtubule and mitosis dynamics
- Ubiquitin and proteasome pathways
- Peroxisome Proliferator-Activated Receptors
- Lipid metabolism and biosynthesis
- Sphingolipid Metabolism and Signaling
- Neuroscience and Neuropharmacology Research
- Heat shock proteins research
- Erythrocyte Function and Pathophysiology
- Lipid Membrane Structure and Behavior
- Cancer Genomics and Diagnostics
- Trace Elements in Health
- Protist diversity and phylogeny
- Viral Infectious Diseases and Gene Expression in Insects
- Peptidase Inhibition and Analysis
- Micro and Nano Robotics
- Ferroptosis and cancer prognosis
- Advanced Electron Microscopy Techniques and Applications
- Advanced Drug Delivery Systems
University of Michigan
2007-2021
University of California, Berkeley
2011-2014
Berkeley College
2013
Brown University
2012
Wilmington University
2011
AstraZeneca (United States)
2011
Merck & Co., Inc., Rahway, NJ, USA (United States)
2006-2008
Albert Einstein College of Medicine
1997-2002
Yeshiva University
2001-2002
Amada (Japan)
2002
Yeast members of the ORMDL family endoplasmic reticulum (ER) membrane proteins play a central role in lipid homeostasis and protein quality control. In absence yeast Orm1 Orm2, accumulation long chain base, sphingolipid precursor, suggests dysregulation synthesis. Physical interaction between Orm2 serine palmitoyltransferase, responsible for first committed step synthesis, further supports Orm regulating Phospholipid is also affected orm1 Δ orm2 cells: cells are inositol auxotrophs with...
Correct sorting of proteins is essential to generate and maintain the identity function different cellular compartments. In this study we demonstrate role lipid rafts in biosynthetic delivery Pma1p, major plasma membrane proton ATPase, cell surface. Disruption led mistargeting Pma1p vacuole. Conversely, Pma1-7, an ATPase mutant that mistargeted vacuole, was shown exhibit impaired raft association. One previously identified suppressors, multicopy AST1, not only restored surface but also...
Doing the Side Step The molecular motor, dynein, contains two ring domains responsible for its movement along microtubule. However, how rings move relative to each other during processive motility and whether dynein processivity requires interhead coordination are unclear. To directly observe “walks” microtubules, DeWitt et al. (p. 221 , published online 8 December) performed advanced fluorescence-imaging studies follow both motor of a single at nanometer resolution. data suggest that heads...
In this study we show that the plasma membrane [H+]ATPase of Saccharomyces cerevisiae is phosphorylated on multiple Ser and Thr residues in vivo. Phosphorylation occurs during movement newly synthesized ATPase from ER to cell surface, as revealed by analysis temperature-sensitive sec mutants blocked at successive steps secretory pathway. Two-dimensional phosphopeptide indicates that, although most sites are or before arrival vesicles, some phosphopeptides unique membrane. membrane-specific...
Accurate chromosome segregation requires the precise coordination of events during cell cycle. Replicated sister chromatids are held together while they properly attached to and aligned by mitotic spindle at metaphase. At anaphase, links between sisters must be promptly dissolved allow rapidly separate them opposite poles. To isolate genes involved in behavior mitosis, we microscopically screened a temperature-sensitive collection budding yeast mutants that contain GFP-marked chromosome....
Sphingolipids are critical components of membranes and sphingolipid metabolites also serve as signaling molecules. Yeast Orm1 Orm2 belong to a conserved family ER membrane proteins that regulate serine palmitoyltransferase, catalyzing the first rate-limiting step in synthesis. We now show synthesis via is target TOR which regulates cell growth response nutritional signals. phosphorylation dependent on Tap42-phosphatase complex acts downstream protein kinase 1; temperature-sensitive tap42-11...
A novel genetic selection was used to identify genes regulating traffic in the yeast endosomal system. We took advantage of a temperature-sensitive mutant PMA1, encoding plasma membrane ATPase, which newly synthesized Pma1 is mislocalized vacuole via endosome. Diversion from vacuolar delivery and rerouting major mechanism suppression pma1(ts). 16 independent suppressor pma1 (sop) mutants were isolated. Identification corresponding reveals eight that are identical with VPS required for...
Sphingolipids are structural components of membranes, and sphingolipid metabolites serve as signaling molecules. The first rate-limiting step in synthesis is catalyzed by serine palmitoyltransferase (SPT). recently discovered SPT-associated proteins, Orm1 Orm2, critical regulators sphingolipids. Orm protein phosphorylation mediating feedback regulation SPT activity occurs response to multiple intermediates, including long chain base complex Both branches the TOR network, TORC1 TORC2,...
Cells have a variety of strategies for dealing with misfolded proteins. Heat shock response involves transcriptional induction chaperones to promote and/or correct folding, and also activation the ubiquitin/proteasome system degrade defective In secretory pathway, it is primarily luminal or unassembled proteins that trigger unfolded protein which, like heat shock, induces components endoplasmic reticulum (ER)-associated degradation (ERAD) pathway. To understand cellular polytopic membrane we...
The vacuolar proton-translocating ATPase (V-ATPase) plays a major role in organelle acidification and works together with other ion transporters to maintain pH homeostasis eukaryotic cells. We analyzed requirement for V-ATPase activity protein trafficking the yeast secretory pathway. Deficiency of caused by subunit deletion or glucose deprivation results missorting newly synthesized plasma membrane proteins Pma1 Can1 directly from Golgi vacuole. Vacuolar mislocalization is dependent on Gga...
Very long chain fatty acids (VLCFAs) are essential with multiple functions, including ceramide synthesis. Although the components of VLCFA biosynthetic machinery have been elucidated, how their activity is regulated to meet cell's metabolic demand remains unknown. The goal this study was identify mechanisms that regulate rate synthesis, and we discovered acid elongase Elo2 by phosphorylation. phosphorylation induced upon inhibition TORC1 requires GSK3. Expression nonphosphorylatable...
An insulin-containing fusion protein (ICFP, encoding the yeast prepro-α factor leader peptide fused via a lysine-arginine cleavage site to single chain insulin) has been expressed in Saccharomyces cerevisiae where it is inefficiently secreted. Single gene disruptions have identified that cause enhanced immunoreactive insulin secretion (eis). Five out of six eis mutants prove be vacuolar sorting (vps)8, vps35, vps13, vps4, and vps36, which affect Golgi↔endosome trafficking. Indeed, wild-type...
Pma1 is a plasma membrane H + -ATPase whose activity at the cell surface essential for viability. In this paper we describe temperature-sensitive pma1 allele, - 10 (with two point mutations in first cytoplasmic loop of Pma1), which newly synthesized mutant protein fails to remain stable 37°C. Instead, Pma1-10 appears undergo internalization vacuolar degradation manner dependent on End4, Vps27, Doa4, and Pep4. By contrast with wild-type Pma1, hypophosphorylated associate Triton-insoluble...
The plasma membrane H + -ATPase, Pma1, is an essential and long-lived integral protein. Previous work has demonstrated that the Pma1-D378N mutant a substrate for endoplasmic reticulum (ER)-associated degradation causes dominant negative effect on cell growth by preventing ER export of wild-type Pma1. We now show ubiquitylated, it heterooligomerizes with resulting in ubiquitylation ER-associated In temperature-sensitive lcb1-100 cells, defective sphingoid base synthesis, Pma1 fails to...
Pma1-7 is a mutant plasma membrane ATPase that impaired in targeting to the cell surface at 37 degrees C and delivered instead endosomal/vacuolar pathway for degradation. We have proposed substrate Golgibased quality control mechanism. By contrast with wild-type Pma1, ubiquitinated. Ubiquitination endosomal of dependent on Rsp5-Bul1-Bul2 ubiquitin ligase protein complex but not transmembrane Tul1. Analysis ubiquitination mutants blocked transport various steps secretory suggests occurs after...
The plasma membrane ATPase, encoded by PMA1, is delivered to the cell surface via secretory pathway. Previously, we characterized a temperature-sensitive pma1 mutant in which newly synthesized Pma1-7 not but mislocalized instead vacuole at 37°C. Severalvps mutants, are defective vacuolar protein sorting, suppress targeting-defective allowing Pma1 move once again membrane. In this study, have analyzed trafficking endosomal system monitoring movement of vps36, vps1, andvps8 mutants. Upon...
Here we report the development and miniaturization of a cell-free enzyme assay for ultra-high-throughput screening (uHTS) inhibitors two potential drug targets obesity cancer: fatty acid synthase (FAS) acetyl-coenzyme A (CoA) carboxylase (ACC) 2. This detects CoA, product FAS-catalyzed condensation malonyl-CoA acetyl-CoA. The free thiol CoA can react with 7-diethylamino-3-(4'-maleimidylphenyl)-4-methylcoumarin (CPM), profluorescent coumarin maleimide derivative that becomes fluorescent upon...
One major cause of endoplasmic reticulum (ER) stress is homeostatic imbalance between biosynthetic protein folding and capacity. Cells utilize mechanisms such as the unfolded response (UPR) to cope with ER stress. Nevertheless, when prolonged or severe, cell death may occur, accompanied by production mitochondrial reactive oxygen species (ROS). Using a yeast model (Saccharomyces cerevisiae), we describe an innate, adaptive increase select proteins, O2 consumption survival. The allows cells...