3P136 Potential role of interaction between IC74 and LC8 of cytoplasmic dynein complex in intracellular transport in mammalian cells(Molecular motors,Oral Presentations)

The hemagglutinin (HA) of influenza virus has been used as a model system to study the biosynthesis and intracellular transport of integral membrane proteins in mammalian cells. To investigate the role of protein structure in facilitating transport along the secretory pathway, we have examined the expression in monkey CV-1 cells of a large number of mutant HA molecules. The majority of the HA mutants do not progress along the secretory pathway and accumulate in the endoplasmic reticulum (ER), and we have shown that assembly of newly-synthesized HA monomers into correctly folded trimeric structures is required for transport of the protein to the Golgi apparatus. By contrast, only one HA mutant has beegn characterized whose transport is blocked at a post-Golgi stage of the pathway and thus little is known about the factors involved in the sorting of the HA molecule from the Golgi apparatus to the plasma membrane (PM). In this study we are using electron microscopy to precisely define the intracellular site of accumulation of two mutant HAs whose transport is blocked at different stages of the secretory pathway. In mutant HAJS67, a cysteine residue (cys67) involved in a key disulfide bond has been substituted by a serine residue. In mutant HA164, the 10 amino acid cytoplasmic tail of the wild-type HA has been replaced by a non-homologous sequence of 16 amino acids. Biochemical and immunof1uoresence analyses have indicated that HAJS67 molecules remain in the ER compartment while HA164 is largely confined to a post-Golgi compartment, possibly the trans Golgi network (TGN).

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Dynein Supports Motility of Endoplasmic Reticulum in the FungusUstilago maydis

Molecular Biology of the Cell ◽

10.1091/mbc.01-10-0475 ◽

2002 ◽

Vol 13 (3) ◽

pp. 965-977 ◽

Cited By ~ 79

Author(s):

Roland Wedlich-Söldner ◽

Irene Schulz ◽

Anne Straube ◽

Gero Steinberg

Keyword(s):

Endoplasmic Reticulum ◽

Golgi Apparatus ◽

Intracellular Transport ◽

Fluorescent Protein ◽

Brefeldin A ◽

Cytoplasmic Dynein ◽

Organelle Transport ◽

Minor Importance ◽

Dependent Transport

The endoplasmic reticulum (ER) of most vertebrate cells is spread out by kinesin-dependent transport along microtubules, whereas studies in Saccharomyces cerevisiae indicated that motility of fungal ER is an actin-based process. However, microtubules are of minor importance for organelle transport in yeast, but they are crucial for intracellular transport within numerous other fungi. Herein, we set out to elucidate the role of the tubulin cytoskeleton in ER organization and dynamics in the fungal pathogen Ustilago maydis. An ER-resident green fluorescent protein (GFP)-fusion protein localized to a peripheral network and the nuclear envelope. Tubules and patches within the network exhibited rapid dynein-driven motion along microtubules, whereas conventional kinesin did not participate in ER motility. Cortical ER organization was independent of microtubules or F-actin, but reformation of the network after experimental disruption was mediated by microtubules and dynein. In addition, a polar gradient of motile ER-GFP stained dots was detected that accumulated around the apical Golgi apparatus. Both the gradient and the Golgi apparatus were sensitive to brefeldin A or benomyl treatment, suggesting that the gradient represents microtubule-dependent vesicle trafficking between ER and Golgi. Our results demonstrate a role of cytoplasmic dynein and microtubules in motility, but not peripheral localization of the ER inU. maydis.

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Proprotein cleavage of E-cadherin by furin in baculovirus over-expression system: potential role of other convertases in mammalian cells

FEBS Letters ◽

10.1016/s0014-5793(98)01330-1 ◽

1998 ◽

Vol 438 (3) ◽

pp. 306-310 ◽

Cited By ~ 50

Author(s):

Horst Posthaus ◽

Claire M. Dubois ◽

Marie-Hélène Laprise ◽

Francine Grondin ◽

Maja M. Suter ◽

...

Keyword(s):

Mammalian Cells ◽

Potential Role ◽

Expression System ◽

Over Expression ◽

E Cadherin

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Cell surface transport, oligomerization, and endocytosis of chimeric type II glycoproteins: role of cytoplasmic and anchor domains

Molecular and Cellular Biology ◽

10.1128/mcb.11.5.2675-2685.1991 ◽

1991 ◽

Vol 11 (5) ◽

pp. 2675-2685

Author(s):

A Kundu ◽

M A Jabbar ◽

D P Nayak

Keyword(s):

Influenza Virus ◽

Cell Surface ◽

Mammalian Cells ◽

Intracellular Transport ◽

Cytoplasmic Domain ◽

Type Ii ◽

Human Influenza Virus ◽

Chimeric Genes ◽

Signal Anchor

We investigated the role of cytoplasmic and anchor domains of type II glycoproteins in intracellular transport, oligomerization, and endocytosis by expressing the wild-type and chimeric genes in mammalian cells. Chimeric genes were constructed by exchanging the DNA segments that encode the cytoplasmic and anchor domains between the human influenza virus (A/WSN/33) neuraminidase (NA) and transferrin receptor (TR). The chimeric proteins in which domains were exchanged precisely were productively targeted to the cell surface. However, the proteins appeared to assemble differently in the intracellular compartment. For example, while TR existed predominantly as a dimer, NATR delta 90, containing the cytoplasmic and signal-anchor domains of NA and the ectodomain of TR, was present as a tetramer, a dimer, and a monomer. Similarly, the influenza virus NA existed predominantly as a tetramer but TRNA delta 35, in which the cytoplasmic and signal-anchor domains of TR were joined to the ectodomain of NA, existed predominantly as a dimer, suggesting that the cytoplasmic and anchor domains of type II glycoproteins affect the subunit assembly of heterologous ectodomains. In addition, we analyzed the role of the cytoplasmic domain in endocytosis. NA and NATR delta 90 did not undergo endocytosis, whereas both TR and TRNA delta 35 were internalized efficiently, demonstrating that the NH2 cytoplasmic domain of TR was capable of internalizing a heterologous ectodomain (NA) from the cell surface.

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Double Edge Sword Behavior of Carbendazim: A Potent Fungicide With Anticancer Therapeutic Properties

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520616666161221113623 ◽

2018 ◽

Vol 18 (1) ◽

pp. 38-45 ◽

Cited By ~ 5

Author(s):

Karan Goyal ◽

Ajay Sharma ◽

Ridhima Arya ◽

Rohit Sharma ◽

Girish K. Gupta ◽

...

Keyword(s):

Mammalian Cells ◽

Potential Role ◽

Anticancer Agent ◽

Significant Proportion ◽

Dual Role ◽

Pharmacokinetic Studies ◽

Phase I Clinical Trials ◽

Discovery Research ◽

Drug Discovery Research

Background: A number of benzimidazole derivatives such as benomyl and carbendazim have been known for their potential role as agricultural fungicides. Simultaneously carbendazim has also been found to inhibit proliferation of mammalian tumor cells specifically drug and multidrug resistant cell lines. Objective: To understand the dual role of Carbendazim as a fungicide and an anticancer agent, the study has been planned referring to the earlier studies in literature. Results: Studies carried out with fungal and mammalian cells have highlighted the potential role of carbendazim in inhibiting proliferation of cells, thereby exhibiting therapeutic implications against cancer. Because of its promising preclinical antitumor activity, Carbendazim had undergone phase I clinical trials and is under further clinical investigations for the treatment of cancer. A number of theoretical interactions have been pinpointed. There are many anticancer drugs in the market, but their usefulness is limited because of drug resistance in a significant proportion of patients. The hunger for newer drugs drives anticancer drug discovery research on a global platform and requires innovations to ensure a sustainable pipeline of lead compounds. Conclusion: Current review highlights the dual role of carbendazim as a fungicide and an anticancer agent. Further, the harmful effects of carbendazim and emphasis upon the need for more pharmacokinetic studies and pharmacovigilance data to ascertain its clinical significance, have also been discussed.

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3P163 Role of γ-subunit N-terminal residues in F_1-ATPase rotation revealed by γ-β fusion mutants(Molecular motors,Oral Presentations)

Seibutsu Butsuri ◽

10.2142/biophys.47.s243_4 ◽

2007 ◽

Vol 47 (supplement) ◽

pp. S243

Author(s):

Ayako Kohori ◽

Katsuyuki Shiroguchi ◽

Shou Furuike ◽

Masasuke Yoshida ◽

Kazuhiko Kinosita

Keyword(s):

Molecular Motors ◽

Γ Subunit ◽

Oral Presentations

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Actin modulates shape and mechanics of tubular membranes

Science Advances ◽

10.1126/sciadv.aaz3050 ◽

2020 ◽

Vol 6 (17) ◽

pp. eaaz3050

Author(s):

A. Allard ◽

M. Bouzid ◽

T. Betz ◽

C. Simon ◽

M. Abou-Ghali ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Mammalian Cells ◽

Intracellular Transport ◽

Plant Cells ◽

Tube Surface ◽

Apparent Contradiction ◽

Single Tube ◽

Tubular Membrane ◽

Tubular Membranes

The actin cytoskeleton shapes cells and also organizes internal membranous compartments. In particular, it interacts with membranes for intracellular transport of material in mammalian cells, yeast, or plant cells. Tubular membrane intermediates, pulled along microtubule tracks, are formed during this process and destabilize into vesicles. While the role of actin in tubule destabilization through scission is suggested, literature also provides examples of actin-mediated stabilization of membranous structures. To directly address this apparent contradiction, we mimic the geometry of tubular intermediates with preformed membrane tubes. The growth of an actin sleeve at the tube surface is monitored spatiotemporally. Depending on network cohesiveness, actin is able to entirely stabilize or locally maintain membrane tubes under pulling. On a single tube, thicker portions correlate with the presence of actin. These structures relax over several minutes and may provide enough time and curvature geometries for other proteins to act on tube stability.

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Specific KIF1A–adaptor interactions control selective cargo recognition

The Journal of Cell Biology ◽

10.1083/jcb.202105011 ◽

2021 ◽

Vol 220 (10) ◽

Author(s):

Jessica J.A. Hummel ◽

Casper C. Hoogenraad

Keyword(s):

Motor Activity ◽

Family Member ◽

Posttranslational Modifications ◽

Molecular Motors ◽

Synaptic Vesicles ◽

Intracellular Transport ◽

Dense Core ◽

Dense Core Vesicles ◽

Transport Vesicles

Intracellular transport in neurons is driven by molecular motors that carry many different cargos along cytoskeletal tracks in axons and dendrites. Identifying how motors interact with specific types of transport vesicles has been challenging. Here, we use engineered motors and cargo adaptors to systematically investigate the selectivity and regulation of kinesin-3 family member KIF1A–driven transport of dense core vesicles (DCVs), lysosomes, and synaptic vesicles (SVs). We dissect the role of KIF1A domains in motor activity and show that CC1 regulates autoinhibition, CC2 regulates motor dimerization, and CC3 and PH mediate cargo binding. Furthermore, we identify that phosphorylation of KIF1A is critical for binding to vesicles. Cargo specificity is achieved by specific KIF1A adaptors; MADD/Rab3GEP links KIF1A to SVs, and Arf-like GTPase Arl8A mediates interactions with DCVs and lysosomes. We propose a model where motor dimerization, posttranslational modifications, and specific adaptors regulate selective KIF1A cargo trafficking.

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Actin modulates shape and mechanics of tubular membranes

10.1101/712505 ◽

2019 ◽

Author(s):

A. Allard ◽

M. Bouzid ◽

T. Betz ◽

C. Simon ◽

M. Abou-Ghali ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Mammalian Cells ◽

Intracellular Transport ◽

Plant Cells ◽

Tube Surface ◽

Apparent Contradiction ◽

Single Tube ◽

Tubular Membrane ◽

Tubular Membranes

The actin cytoskeleton shapes cells and also organizes internal membranous compartments. In particular, it interacts with membranes in intracellular transport of material in mammalian cells, yeast or plant cells. Tubular membrane intermediates, pulled along microtubule tracks, are involved during these processes, and destabilize into vesicles. While the role of actin in this destabilization process is still debated, literature also provide examples of membranous structures stabilization by actin. To directly address this apparent contradiction, we mimic the geometry of tubular intermediates with preformed membrane tubes. The growth of an actin sleeve at the tube surface is monitored spatio-temporally. Depending on network cohesiveness, actin is able to stabilize, or maintain membrane tubes under pulling. Indeed, on a single tube, thicker portions correlate with the presence of actin. Such structures relax over several minutes, and may provide enough time and curvature geometries for other proteins to act on tube stability.

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Cell surface transport, oligomerization, and endocytosis of chimeric type II glycoproteins: role of cytoplasmic and anchor domains.

Molecular and Cellular Biology ◽

10.1128/mcb.11.5.2675 ◽

1991 ◽

Vol 11 (5) ◽

pp. 2675-2685 ◽

Cited By ~ 14

Author(s):

A Kundu ◽

M A Jabbar ◽

D P Nayak

Keyword(s):

Influenza Virus ◽

Cell Surface ◽

Mammalian Cells ◽

Intracellular Transport ◽

Cytoplasmic Domain ◽

Type Ii ◽

Human Influenza Virus ◽

Chimeric Genes ◽

Signal Anchor

We investigated the role of cytoplasmic and anchor domains of type II glycoproteins in intracellular transport, oligomerization, and endocytosis by expressing the wild-type and chimeric genes in mammalian cells. Chimeric genes were constructed by exchanging the DNA segments that encode the cytoplasmic and anchor domains between the human influenza virus (A/WSN/33) neuraminidase (NA) and transferrin receptor (TR). The chimeric proteins in which domains were exchanged precisely were productively targeted to the cell surface. However, the proteins appeared to assemble differently in the intracellular compartment. For example, while TR existed predominantly as a dimer, NATR delta 90, containing the cytoplasmic and signal-anchor domains of NA and the ectodomain of TR, was present as a tetramer, a dimer, and a monomer. Similarly, the influenza virus NA existed predominantly as a tetramer but TRNA delta 35, in which the cytoplasmic and signal-anchor domains of TR were joined to the ectodomain of NA, existed predominantly as a dimer, suggesting that the cytoplasmic and anchor domains of type II glycoproteins affect the subunit assembly of heterologous ectodomains. In addition, we analyzed the role of the cytoplasmic domain in endocytosis. NA and NATR delta 90 did not undergo endocytosis, whereas both TR and TRNA delta 35 were internalized efficiently, demonstrating that the NH2 cytoplasmic domain of TR was capable of internalizing a heterologous ectodomain (NA) from the cell surface.

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