92 results match your criteria sec15


The Sur7/PalI family transmembrane protein Tos7 (Yol019w) plays a role in secretion in budding yeast.

Fungal Genet Biol 2020 Nov 28;144:103467. Epub 2020 Sep 28.

Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China; Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Wuhan, China. Electronic address:

Tos7 (Yol019w) is a Sur7/PalI family transmembrane protein in the budding yeast Saccharomyces cerevisiae. Since the deletion of TOS7 did not affect growth or cell morphology, the cellular roles of Tos7 have not been established previously. Here, we show that high-copy TOS7 expression suppressed the growth defect of the secretion-defective RGA1-C term-overexpressing mutant and sec15-1 mutant. Read More

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November 2020

Exocyst components promote an incompatible interaction between Glycine max (soybean) and Heterodera glycines (the soybean cyst nematode).

Sci Rep 2020 09 14;10(1):15003. Epub 2020 Sep 14.

Department of Biological Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.

Vesicle and target membrane fusion involves tethering, docking and fusion. The GTPase SECRETORY4 (SEC4) positions the exocyst complex during vesicle membrane tethering, facilitating docking and fusion. Glycine max (soybean) Sec4 functions in the root during its defense against the parasitic nematode Heterodera glycines as it attempts to develop a multinucleate nurse cell (syncytium) serving to nourish the nematode over its 30-day life cycle. Read More

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September 2020

Roles of the PH, coiled-coil and SAM domains of the yeast polarity protein Boi2 in polarity-site localization and function in polarized growth.

Curr Genet 2020 Dec 12;66(6):1101-1115. Epub 2020 Jul 12.

Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, 430072, China.

Boi1 and Boi2 are paralogous proteins essential for bud formation in budding yeast. So far, the domains that target Boi1/Boi2 to the polarity sites and function in bud formation are not well understood. Here, we report that a coiled-coil domain of Boi2 cooperates with the adjacent PH domain to confer Boi2's bud-cortex localization and major function in cell growth. Read More

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December 2020

Exocyst Genes Are Essential for Recycling Membrane Proteins and Maintaining Slit Diaphragm in Nephrocytes.

J Am Soc Nephrol 2020 05 1;31(5):1024-1034. Epub 2020 Apr 1.

Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland

Background: Studies have linked mutations in genes encoding the eight-protein exocyst protein complex to kidney disease, but the underlying mechanism is unclear. Because nephrocytes share molecular and structural features with mammalian podocytes, they provide an efficient model for studying this issue.

Methods: We silenced genes encoding exocyst complex proteins specifically in nephrocytes and studied the effects on protein reabsorption by lacuna channels and filtration by the slit diaphragm. Read More

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Developmental expression, co-localization and genetic interaction of exocyst component Sec15 with Rab11 during Drosophila development.

Exp Cell Res 2019 08 7;381(1):94-104. Epub 2019 May 7.

Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221 005, India.

Sec15, a component of an evolutionarily conserved octomeric exocyst complex, has been identified as an interactor of GTP-bound Rab11 in mammals and Drosophila which shows its role in secretion in yeast and intracellular vesicle transport. Here, we report the expression patterns of Drosophila Sec15 (DSec15) transcript and Sec15 protein during Drosophila development. At early embryonic stages, a profound level of maternally loaded DSec15 transcript and protein is found. Read More

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remodels the plasma membrane-derived vacuole by utilizing exocyst components as tethers.

J Cell Biol 2018 11 1;217(11):3863-3872. Epub 2018 Oct 1.

Department of Microbial Pathogenesis, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT

During the initial stage of infection, secretes effectors that promote the fusion of endoplasmic reticulum (ER)-derived vesicles with the -containing vacuole (LCV). This fusion leads to a remodeling of the plasma membrane (PM)-derived LCV into a specialized ER-like compartment that supports bacterial replication. Although the effector DrrA has been shown to activate the small GTPase Rab1, it remains unclear how DrrA promotes the tethering of host vesicles with the LCV. Read More

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November 2018

Anthrax edema toxin disrupts distinct steps in Rab11-dependent junctional transport.

PLoS Pathog 2017 Sep 25;13(9):e1006603. Epub 2017 Sep 25.

Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States of America.

Various bacterial toxins circumvent host defenses through overproduction of cAMP. In a previous study, we showed that edema factor (EF), an adenylate cyclase from Bacillus anthracis, disrupts endocytic recycling mediated by the small GTPase Rab11. As a result, cargo proteins such as cadherins fail to reach inter-cellular junctions. Read More

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September 2017

Collaboration between Distinct Rab Small GTPase Trafficking Circuits Mediates Bacterial Clearance from the Bladder Epithelium.

Cell Host Microbe 2017 Sep;22(3):330-342.e4

Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA; Program in Emerging Infectious Diseases, Duke-National University of Singapore, Singapore 169857, Singapore.

Rab small GTPases control membrane trafficking through effectors that recruit downstream mediators such as motor proteins. Subcellular trafficking typically involves multiple Rabs, with each specific step mediated by a distinct Rab protein. We describe a collaboration between two distinct Rab-protein-orchestrated trafficking circuits in bladder epithelial cells (BECs) that expels intracellular uropathogenic Escherichia coli (UPEC) from their intracellular niche. Read More

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September 2017

Role of Saccharomyces cerevisiae TAN1 (tRNA acetyltransferase) in eukaryotic initiation factor 2B (eIF2B)-mediated translation control and stress response.

3 Biotech 2017 Jul 4;7(3):223. Epub 2017 Jul 4.

Faculty of Applied Sciences and Biotechnology, Shoolini University, Solan, Himachal Pradesh, India.

Eukaryotic initiation factor 2B (eIF2B) controls the first step of translation by catalyzing guanine nucleotide exchange on eukaryotic initiation factor 2 (eIF2). Mutations in the genes encoding eIF2B subunits inhibit the nucleotide exchange and eventually slow down the process of translation, causing vanishing white matter disease. We constructed a Saccharomyces cerevisiae genomic DNA library in YEp24 vector and screened it for the identification of extragenic suppressors of eIF2B mutations, corresponding to human eIF2B mutations. Read More

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The Trypanosome Exocyst: A Conserved Structure Revealing a New Role in Endocytosis.

PLoS Pathog 2017 01 23;13(1):e1006063. Epub 2017 Jan 23.

Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom.

Membrane transport is an essential component of pathogenesis for most infectious organisms. In African trypanosomes, transport to and from the plasma membrane is closely coupled to immune evasion and antigenic variation. In mammals and fungi an octameric exocyst complex mediates late steps in exocytosis, but comparative genomics suggested that trypanosomes retain only six canonical subunits, implying mechanistic divergence. Read More

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January 2017

Crystal structure of Sec10, a subunit of the exocyst complex.

Sci Rep 2017 01 18;7:40909. Epub 2017 Jan 18.

Structural Biology Laboratory, Structural Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.

The exocyst complex is a heterooctameric protein complex composed of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84. This complex plays an essential role in trafficking secretory vesicles to the plasma membrane through its interaction with phosphatidylinositol 4,5-bisphosphate and small GTPases. To date, the near-full-length structural information of each subunit has been limited to Exo70, although the C-terminal half structures of Sec6, Sec15 and Exo84 and the structures of the small GTPase-binding domains of Sec3, Sec5 and Exo84 have been reported. Read More

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January 2017

Sec8 modulates TGF-β induced EMT by controlling N-cadherin via regulation of Smad3/4.

Cell Signal 2017 01 18;29:115-126. Epub 2016 Oct 18.

Department of Dentistry, Oral and Maxillofacial Surgery, Plastic and Reconstructive Surgery, School of Medicine, Yamagata University, 2-2-2 Iidanishi, Yamagata, Japan.

Sec8 is one of the subunits of the exocyst, which is an evolutionarily conserved complex of eight proteins, comprising Sec3 (EXOC1), Sec5 (EXOC2), Sec6 (EXOC3), Sec8 (EXOC4), Sec10 (EXOC5), Sec15 (EXOC6), Exo70 (EXOC7), and Exo84 (EXOC8) subunits. Sec8 knockout mice embryos initiate gastrulation but are unable to progress beyond the primitive streak stage and die shortly. During embryonic development, the first epithelial-mesenchymal transition (EMT) event occurs at gastrulation. Read More

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January 2017

Diverse Functions and Signal Transduction of the Exocyst Complex in Tumor Cells.

J Cell Physiol 2017 05 22;232(5):939-957. Epub 2016 Dec 22.

Department of Dentistry, Oral and Maxillofacial Surgery, Plastic and Reconstructive Surgery, School of Medicine, Yamagata University, Yamagata, Japan.

The exocyst complex is a large conserved hetero-oligomeric complex that consists of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70, and Exo84 subunits. It has been implicated in the targeting of vesicles for regulated exocytosis in various cell types, and is also important for targeted exocytosis of post-Golgi transport vesicles to the plasma membrane. The exocyst complex is essential for membrane growth, secretion, and function during exocytosis and endocytosis. Read More

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Cell cycle-dependent phosphorylation of Sec4p controls membrane deposition during cytokinesis.

J Cell Biol 2016 09;214(6):691-703

Department of Molecular Medicine, Cornell University, Ithaca, NY 14853

Intracellular trafficking is an essential and conserved eukaryotic process. Rab GTPases are a family of proteins that regulate and provide specificity for discrete membrane trafficking steps by harnessing a nucleotide-bound cycle. Global proteomic screens have revealed many Rab GTPases as phosphoproteins, but the effects of this modification are not well understood. Read More

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September 2016

Retraction for Chavez-Dozal et al. Functional Analysis of the Exocyst Subunit Sec15 in Candida albicans.

Eukaryot Cell 2015 Dec;14(12):ii

Section of Infectious Diseases, New Mexico VA Healthcare System, Albuquerque, New Mexico, USA Division of Infectious Diseases, University of New Mexico Health Science Center, Albuquerque, New Mexico, USA.

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December 2015

Regulation of membrane traffic by Rab GEF and GAP cascades.

Authors:
Peter Novick

Small GTPases 2016 10 18;7(4):252-256. Epub 2016 Jul 18.

a Department of Cellular and Molecular Medicine , University of California San Diego , La Jolla , CA , USA.

ASBTRACT Rab GTPases serve as master regulators of membrane traffic, each typically controlling several different aspects of a specific stage of membrane traffic by recruiting diverse effector proteins such as cytoskeletal motors, vesicle tethering proteins and regulators of SNARE complex assembly. Rabs, in turn, are regulated by specific guanine nucleotide exchange factors (GEFs), which catalyze the displacement of GDP and binding of GTP, as well as GTPase activating proteins (GAPs) that stimulate the slow intrinsic rate of GTP hydrolysis. Here I review our studies on the final stages of the yeast secretory pathway that have led us to propose that adjacent Rabs on a pathway are networked to one another through their regulators; specifically we have shown that the Rab, Ypt32, in its GTP-bound form recruits both Sec2, the GEF that activates the downstream Rab, Sec4, as well as Gyp1, the GAP that inactivates the upstream Rab, Ypt1. Read More

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October 2016

Sec15 links bud site selection to polarised cell growth and exocytosis in Candida albicans.

Sci Rep 2016 05 26;6:26464. Epub 2016 May 26.

Institute of Health Sciences, Anhui University, Hefei 230601, China.

The exocyst plays a crucial role in the targeting of secretory vesicles to the plasma membrane during exocytosis. It has been shown to be involved in diverse cellular processes including yeast budding. However, the mechanism of the exocyst regulating yeast budding has not been fully elucidated. Read More

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The exocyst in Candida albicans polarized secretion and filamentation.

Curr Genet 2016 May 13;62(2):343-6. Epub 2016 Jan 13.

Section of Infectious Diseases, New Mexico VA Healthcare System, 1501 San Pedro SE, Mail Code 111-J, Albuquerque, NM, 87108, USA.

The exocyst is an octameric complex that orchestrates the docking and tethering of vesicles to the plasma membrane during exocytosis and is fundamental for key biological processes including growth and establishment of cell polarity. Although components of the exocyst are well conserved among fungi, the specific functions of each component of the exocyst complex unique to Candida albicans biology and pathogenesis are not fully understood. This commentary describes recent findings regarding the role of exocyst subunits Sec6 and Sec15 in C. Read More

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The casein kinases Yck1p and Yck2p act in the secretory pathway, in part, by regulating the Rab exchange factor Sec2p.

Mol Biol Cell 2016 Feb 23;27(4):686-701. Epub 2015 Dec 23.

Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093

Sec2p is a guanine nucleotide exchange factor that activates Sec4p, the final Rab GTPase of the yeast secretory pathway. Sec2p is recruited to secretory vesicles by the upstream Rab Ypt32p acting in concert with phosphatidylinositol-4-phosphate (PI(4)P). Sec2p also binds to the Sec4p effector Sec15p, yet Ypt32p and Sec15p compete against each other for binding to Sec2p. Read More

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February 2016

Septin-Dependent Assembly of the Exocyst Is Essential for Plant Infection by Magnaporthe oryzae.

Plant Cell 2015 Nov 13;27(11):3277-89. Epub 2015 Nov 13.

School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom

Magnaporthe oryzae is the causal agent of rice blast disease, the most devastating disease of cultivated rice (Oryza sativa) and a continuing threat to global food security. To cause disease, the fungus elaborates a specialized infection cell called an appressorium, which breaches the cuticle of the rice leaf, allowing the fungus entry to plant tissue. Here, we show that the exocyst complex localizes to the tips of growing hyphae during vegetative growth, ahead of the Spitzenkörper, and is required for polarized exocytosis. Read More

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November 2015

Functional Analysis of the Exocyst Subunit Sec15 in Candida albicans.

Eukaryot Cell 2015 Dec 9;14(12):1228-39. Epub 2015 Oct 9.

Section of Infectious Diseases, New Mexico VA Healthcare System, Albuquerque, New Mexico, USA Division of Infectious Diseases, University of New Mexico Health Science Center, Albuquerque, New Mexico, USA

In prior studies of exocyst-mediated late secretion in Candida albicans, we have determined that Sec6 contributes to cell wall integrity, secretion, and filamentation. A conditional mutant lacking SEC6 expression exhibits markedly reduced lateral hyphal branching. In addition, lack of the related t-SNAREs Sso2 and Sec9 also leads to defects in secretion and filamentation. Read More

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December 2015

RNA Silencing of Exocyst Genes in the Stigma Impairs the Acceptance of Compatible Pollen in Arabidopsis.

Plant Physiol 2015 Dec 6;169(4):2526-38. Epub 2015 Oct 6.

Department of Cell and Systems Biology and Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada M5S 3B2

Initial pollen-pistil interactions in the Brassicaceae are regulated by rapid communication between pollen grains and stigmatic papillae and are fundamentally important, as they are the first step toward successful fertilization. The goal of this study was to examine the requirement of exocyst subunits, which function in docking secretory vesicles to sites of polarized secretion, in the context of pollen-pistil interactions. One of the exocyst subunit genes, EXO70A1, was previously identified as an essential factor in the stigma for the acceptance of compatible pollen in Arabidopsis (Arabidopsis thaliana) and Brassica napus. Read More

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December 2015

The Candida albicans Exocyst Subunit Sec6 Contributes to Cell Wall Integrity and Is a Determinant of Hyphal Branching.

Eukaryot Cell 2015 Jul 22;14(7):684-97. Epub 2015 May 22.

Section of Infectious Diseases, New Mexico VA Healthcare System, Albuquerque, New Mexico, USA Division of Infectious Diseases, University of New Mexico Health Science Center, Albuquerque, New Mexico, USA

The yeast exocyst is a multiprotein complex comprised of eight subunits (Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70, and Exo84) which orchestrates trafficking of exocytic vesicles to specific docking sites on the plasma membrane during polarized secretion. To study SEC6 function in Candida albicans, we generated a conditional mutant strain in which SEC6 was placed under the control of a tetracycline-regulated promoter. In the repressed state, the tetR-SEC6 mutant strain (denoted tSEC6) was viable for up to 27 h; thus, all phenotypic analyses were performed at 24 h or earlier. Read More

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Architectures of multisubunit complexes revealed by a visible immunoprecipitation assay using fluorescent fusion proteins.

J Cell Sci 2015 Jun 11;128(12):2351-62. Epub 2015 May 11.

Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan

In this study, we elucidated the architectures of two multisubunit complexes, the BBSome and exocyst, through a novel application of fluorescent fusion proteins. By processing lysates from cells co-expressing GFP and RFP fusion proteins for immunoprecipitation with anti-GFP nanobody, protein-protein interactions could be reproducibly visualized by directly observing the immunoprecipitates under a microscope, and evaluated using a microplate reader, without requiring immunoblotting. Using this 'visible' immunoprecipitation (VIP) assay, we mapped binary subunit interactions of the BBSome complex, and determined the hierarchies of up to four subunit interactions. Read More

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Membrane targeting of the yeast exocyst complex.

Biochim Biophys Acta 2015 Jul 30;1848(7):1481-9. Epub 2015 Mar 30.

Institute of Experimental Botany, Academy of Sciences of the Czech Republic, 165 02 Prague, Czech Republic. Electronic address:

The exocytosis is a process of fusion of secretory vesicles with plasma membrane, which plays a prominent role in many crucial cellular processes, e.g. secretion of neurotransmitters, cytokinesis or yeast budding. Read More

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Assaying the interaction of the Rab guanine nucleotide exchange protein Sec2 with the upstream Rab, a downstream effector, and a phosphoinositide.

Methods Mol Biol 2015 ;1298:85-98

Department of Cellular and Molecular Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.

Rabs are activated by guanine nucleotide exchange proteins, which are in turn controlled by complex regulatory mechanisms. Here we describe several different assays that have been used to delineate the mechanisms by which Sec2p, the exchange factor for the Rab Sec4p, is regulated. These assays assess the interaction of Sec2p with the upstream Rab, Ypt32p, a downstream Sec4p effector, Sec15p, and the lipid, phosphatidylinositol-4-phosphate. Read More

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Oncogenic Ras stimulates Eiger/TNF exocytosis to promote growth.

Development 2014 Dec 19;141(24):4729-39. Epub 2014 Nov 19.

Department of Genetics, Howard Hughes Medical Institute, Yale University School of Medicine, Boyer Center for Molecular Medicine, 295 Congress Avenue, New Haven, CT 06536, USA

Oncogenic mutations in Ras deregulate cell death and proliferation to cause cancer in a significant number of patients. Although normal Ras signaling during development has been well elucidated in multiple organisms, it is less clear how oncogenic Ras exerts its effects. Furthermore, cancers with oncogenic Ras mutations are aggressive and generally resistant to targeted therapies or chemotherapy. Read More

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December 2014

In vitro reconstitution of Rab GTPase-dependent vesicle clustering by the yeast lethal giant larvae/tomosyn homolog, Sro7.

J Biol Chem 2015 Jan 17;290(1):612-24. Epub 2014 Nov 17.

From the Departments of Cell Biology and Physiology and

Intracellular traffic in yeast between the Golgi and the cell surface is mediated by vesicular carriers that tether and fuse in a fashion that depends on the function of the Rab GTPase, Sec4. Overexpression of either of two Sec4 effectors, Sro7 or Sec15, results in the formation of a cluster of post-Golgi vesicles within the cell. Here, we describe a novel assay that recapitulates post-Golgi vesicle clustering in vitro utilizing purified Sro7 and vesicles isolated from late secretory mutants. Read More

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January 2015

Bem1p contributes to secretory pathway polarization through a direct interaction with Exo70p.

J Cell Biol 2014 Oct;207(1):59-72

Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92130

The exocyst serves to tether secretory vesicles to cortical sites specified by polarity determinants, in preparation for fusion with the plasma membrane. Although most exocyst components are brought to these sites by riding on secretory vesicles as they are actively transported along actin cables, Exo70p displays actin-independent localization to these sites, implying an interaction with a polarity determinant. Here we show that Exo70p directly and specifically binds to the polarity determinant scaffold protein Bem1p. Read More

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October 2014

Osh4p is needed to reduce the level of phosphatidylinositol-4-phosphate on secretory vesicles as they mature.

Mol Biol Cell 2014 Nov 27;25(21):3389-400. Epub 2014 Aug 27.

Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093

Phosphatidylinositol-4-phosphate (PI4P) is produced on both the Golgi and the plasma membrane. Despite extensive vesicular traffic between these compartments, genetic analysis suggests that the two pools of PI4P do not efficiently mix with one another. Several lines of evidence indicate that the PI4P produced on the Golgi is normally incorporated into secretory vesicles, but the fate of that pool has been unclear. Read More

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November 2014