scholarly journals Rab coupling protein is selectively degraded by calpain in a Ca2+-dependent manner

2005 ◽  
Vol 389 (1) ◽  
pp. 223-231 ◽  
Author(s):  
Nicolas MARIE ◽  
Andrew J. LINDSAY ◽  
Mary W. McCAFFREY
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Calpain Inhibitor ◽  
Dependent Manner ◽  
Interacting Proteins ◽  
Wild Type ◽  
A431 Cells ◽  
Calcium Dependent ◽  
Coupling Protein ◽  
Calpain Inhibitors

RCP (Rab coupling protein) belongs to the recently identified Rab11-FIPs (Rab11 family of interacting proteins). All the Rab-FIP members have the ability to bind Rab11 tightly via a Rab-binding domain located near their C-termini. RCP belongs to the class I Rab11-FIP subfamily, characterized by the presence of a conserved C2 domain near its N-terminus. The function of this protein in Rab11-dependent membrane trafficking remains to be fully understood. In the present study, we have identified three putative PEST (Pro, Glu, Ser/Thr-rich) sequences in RCP. PEST motifs play a role in targeting a protein for proteolytic degradation. We have demonstrated that RCP undergoes calcium-dependent degradation which can be prevented by specific calpain inhibitors. Using a mutant, lacking the three PEST sequences, RCPΔPEST, we demonstrated that they are necessary for the cleavage of RCP by calpains. When expressed in A431 cells, RCPΔPEST displays significantly greater localization to the plasma membrane, compared with the wild-type protein. Similarly, treatment with the calpain inhibitor, calpeptin, results in the redistribution of endogenous RCP to the periphery of the cell. We propose that once the Rab11/RCP-regulated cargo has been delivered from the endocytic recycling compartment to the plasma membrane, RCP is inactivated by calpain-mediated proteolysis.

In vitro selection of Phytomonas serpens cells resistant to the calpain inhibitor MDL28170: alterations in fitness and expression of the major peptidases and efflux pumps

Parasitology ◽  
2017 ◽  
Vol 145 (3) ◽  
pp. 355-370 ◽  
Author(s):  
SIMONE S. C. OLIVEIRA ◽  
INÊS C. GONÇALVES ◽  
VITOR ENNES-VIDAL ◽  
ANGELA H. C. S. LOPES ◽  
RUBEM F. S. MENNA-BARRETO ◽  
...  
Keyword(s):  
In Vitro Selection ◽  
Oncopeltus Fasciatus ◽  
Calpain Inhibitor ◽  
Insect Vector ◽  
Peptidase Activity ◽  
Wild Type ◽  
Calcium Dependent ◽  
Calpain Inhibitors ◽  
Selection Of

SUMMARYThe species Phytomonas serpens is known to express some molecules displaying similarity to those described in trypanosomatids pathogenic to humans, such as peptidases from Trypanosoma cruzi (cruzipain) and Leishmania spp. (gp63). In this work, a population of P. serpens resistant to the calpain inhibitor MDL28170 at 70 µm (MDLR population) was selected by culturing promastigotes in increasing concentrations of the drug. The only relevant ultrastructural difference between wild-type (WT) and MDLR promastigotes was the presence of microvesicles within the flagellar pocket of the latter. MDLR population also showed an increased reactivity to anti-cruzipain antibody as well as a higher papain-like proteolytic activity, while the expression of calpain-like molecules cross-reactive to anti-Dm-calpain (from Drosophila melanogaster) antibody and calcium-dependent cysteine peptidase activity were decreased. Gp63-like molecules also presented a diminished expression in MDLR population, which is probably correlated to the reduction in the parasite adhesion to the salivary glands of the insect vector Oncopeltus fasciatus. A lower accumulation of Rhodamine 123 was detected in MDLR cells when compared with the WT population, a phenotype that was reversed when MDLR cells were treated with cyclosporin A and verapamil. Collectively, our results may help in the understanding of the roles of calpain inhibitors in trypanosomatids.

scholarly journals Mutant p53 promotes RCP-dependent chemoresistance coinciding with increased delivery of P-glycoprotein to the plasma membrane

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Vinaya Phatak ◽  
Yannick von Grabowiecki ◽  
Justyna Janus ◽  
Leah Officer ◽  
Caron Behan ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Tyrosine Kinases ◽  
Mutant P53 ◽  
Interacting Proteins ◽  
Wild Type ◽  
Glycoprotein P ◽  
P53 Expression ◽  
P Glycoprotein ◽  
Endosomal Recycling ◽  
Coupling Protein

AbstractTP53 is the most frequently mutated gene in cancers. Mutations lead to loss of p53 expression or expression of a mutant protein. Mutant p53 proteins commonly lose wild-type function, but can also acquire novel functions in promoting metastasis and chemoresistance. Previously, we uncovered a role for Rab-coupling protein (RCP) in mutant p53-dependent invasion. RCP promotes endosomal recycling and signalling of integrins and receptor tyrosine kinases. In a screen to identify novel RCP-interacting proteins, we discovered P-glycoprotein (P-gp). Thus, we hypothesised that mutant p53 could promote chemoresistance through RCP-dependent recycling of P-gp. The interaction between RCP and P-gp was verified endogenously and loss of RCP or mutant p53 rendered cells more sensitive to cisplatin and etoposide. In mutant p53 cells we detected an RCP-dependent delivery of P-gp to the plasma membrane upon drug treatment and decreased retention of P-gp substrates. A co-localisation of P-gp and RCP was seen in mutant p53 cells, but not in p53-null cells upon chemotherapeutic exposure. In conclusion, mutant p53 expression enhanced co-localisation of P-gp and RCP to allow for rapid delivery of P-gp to the plasma membrane and increased resistance to chemotherapeutics.

scholarly journals Glycosylation Modulates Plasma Membrane Trafficking of CD24 in Breast Cancer Cells

2021 ◽  
Vol 22 (15) ◽  
pp. 8165
Author(s):  
Amanda Chantziou ◽  
Kostas Theodorakis ◽  
Hara Polioudaki ◽  
Eelco de Bree ◽  
Marilena Kampa ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Plasma Membrane ◽  
Subcellular Localization ◽  
Cancer Cells ◽  
Membrane Trafficking ◽  
Breast Cancer Cells ◽  
Endocytic Pathway ◽  
Cell Periphery ◽  
Wild Type ◽  
Mcf 7

In breast cancer, expression of Cluster of Differentiation 24 (CD24), a small GPI-anchored glycoprotein at the cell periphery, is associated with metastasis and immune escape, while its absence is associated with tumor-initiating capacity. Since the mechanism of CD24 sorting is unknown, we investigated the role of glycosylation in the subcellular localization of CD24. Expression and localization of wild type N36- and/or N52-mutated CD24 were analyzed using immunofluorescence in luminal (MCF-7) and basal B (MDA-MB-231 and Hs578T) breast cancer cells lines, as well as HEK293T cells. Endogenous and exogenously expressed wild type and mutated CD24 were found localized at the plasma membrane and the cytoplasm, but not the nucleoplasm. The cell lines showed different kinetics for the sorting of CD24 through the secretory/endocytic pathway. N-glycosylation, especially at N52, and its processing in the Golgi were critical for the sorting and expression of CD24 at the plasma membrane of HEK293T and basal B type cells, but not of MCF-7 cells. In conclusion, our study highlights the contribution of N-glycosylation for the subcellular localization of CD24. Aberrant N-glycosylation at N52 of CD24 could account for the lack of CD24 expression at the cell surface of basal B breast cancer cells.

scholarly journals Phospholipid flippases enable precursor B cells to flee engulfment by macrophages

2018 ◽  
Vol 115 (48) ◽  
pp. 12212-12217 ◽  
Author(s):  
Katsumori Segawa ◽  
Yuichi Yanagihashi ◽  
Kyoko Yamada ◽  
Chigure Suzuki ◽  
Yasuo Uchiyama ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
B Cells ◽  
B Cell ◽  
Developmental Stages ◽  
Peritoneal Macrophages ◽  
Dependent Manner ◽  
Wild Type ◽  
Immature B Cells ◽  
T Lymphoma ◽  
Precursor B Cells

ATP11A and ATP11C, members of the P4-ATPases, are flippases that translocate phosphatidylserine (PtdSer) from the outer to inner leaflet of the plasma membrane. Using the W3 T lymphoma cell line, we found that Ca2+ ionophore-induced phospholipid scrambling caused prolonged PtdSer exposure in cells lacking both the ATP11A and ATP11C genes. ATP11C-null (ATP11C−/y) mutant mice exhibit severe B-cell deficiency. In wild-type mice, ATP11C was expressed at all B-cell developmental stages, while ATP11A was not expressed after pro−B-cell stages, indicating that ATP11C−/y early B-cell progenitors lacked plasma membrane flippases. The receptor kinases MerTK and Axl are known to be essential for the PtdSer-mediated engulfment of apoptotic cells by macrophages. MerTK−/− and Axl−/− double deficiency fully rescued the lymphopenia in the ATP11C−/y bone marrow. Many of the rescued ATP11C−/y pre-B and immature B cells exposed PtdSer, and these cells were engulfed alive by wild-type peritoneal macrophages, in a PtdSer-dependent manner. These results indicate that ATP11A and ATP11C in precursor B cells are essential for rapidly internalizing PtdSer from the cell surface to prevent the cells’ engulfment by macrophages.

scholarly journals The Receptor for Parathyroid Hormone and Parathyroid Hormone-Related Peptide Is Hydrolyzed and Its Signaling Properties Are Altered by Directly Binding the Calpain Small Subunit

Endocrinology ◽  
2005 ◽  
Vol 146 (5) ◽  
pp. 2336-2344 ◽  
Author(s):  
Masako Shimada ◽  
Matthew J. Mahon ◽  
Peter A. Greer ◽  
Gino V. Segre
Keyword(s):  
Parathyroid Hormone ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Small Subunit ◽  
Hek293 Cells ◽  
Calpain Inhibitor ◽  
Dependent Manner ◽  
Intact Cells ◽  
Calcium Dependent

Abstract We show calcium-dependent, direct binding between the N-terminal portion of the PTH/PTHrP receptor (PTH1R) C-terminal intracellular tail and the calpain small subunit. Binding requires, but may not be limited to, amino acids W474, S475, and W477. The wild-type, full-length rat (r) PTH1R, but not rPTH1R with W474A/W477A substitutions, copurifies with the endogenous calpain small subunit in HEK293 cells. Calpain hydrolyzes ΔNt-rPTH1R, a receptor with a 156-amino acid N-terminal deletion, in a calcium-dependent manner in vitro and in intact cells. Most importantly, PTH stimulation increases the cleavage of ΔNt-rPTH1R and rPTH1R-yellow fluorescent protein in HEK293 cells, and of talin in HEK293 cells expressing rPTH1R-yellow fluorescent protein and in ROS17/2.8 osteoblast-like cells that express rPTH1R endogenously. The absence of calpain in Capn4-null embryonic fibroblasts and the lowered calpain activity in MC3T3-E1 osteoblastic cells due to stable expression of the calpain inhibitor, calpastatin, reduce PTH-stimulated cAMP accumulation. The calpain small subunit is the second protein, in addition to the sodium-hydrogen exchanger regulatory factor, and the first enzyme that binds the PTH1R; PTH1R bound to both of these proteins results in altered PTH signaling.

scholarly journals Apical Membrane Targeting of Nedd4 Is Mediated by an Association of Its C2 Domain with Annexin Xiiib

2000 ◽  
Vol 149 (7) ◽  
pp. 1473-1484 ◽  
Author(s):  
Pamela J. Plant ◽  
Frank Lafont ◽  
Sandra Lecat ◽  
Paul Verkade ◽  
Kai Simons ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Apical Membrane ◽  
Mdck Cells ◽  
Immunogold Electron Microscopy ◽  
Apical Plasma Membrane ◽  
Apical Region ◽  
Apical Surface ◽  
Dependent Manner ◽  
Interacting Proteins ◽  
C2 Domain

Nedd4 is a ubiquitin protein ligase (E3) containing a C2 domain, three or four WW domains, and a ubiquitin ligase HECT domain. We have shown previously that the C2 domain of Nedd4 is responsible for its Ca2+-dependent targeting to the plasma membrane, particularly the apical region of epithelial MDCK cells. To investigate this apical preference, we searched for Nedd4-C2 domain-interacting proteins that might be involved in targeting Nedd4 to the apical surface. Using immobilized Nedd4-C2 domain to trap interacting proteins from MDCK cell lysate, we isolated, in the presence of Ca2+, a ∼35–40-kD protein that we identified as annexin XIII using mass spectrometry. Annexin XIII has two known isoforms, a and b, that are apically localized, although XIIIa is also found in the basolateral compartment. In vitro binding and coprecipitation experiments showed that the Nedd4-C2 domain interacts with both annexin XIIIa and b in the presence of Ca2+, and the interaction is direct and optimal at 1 μM Ca2+. Immunofluorescence and immunogold electron microscopy revealed colocalization of Nedd4 and annexin XIIIb in apical carriers and at the apical plasma membrane. Moreover, we show that Nedd4 associates with raft lipid microdomains in a Ca2+-dependent manner, as determined by detergent extraction and floatation assays. These results suggest that the apical membrane localization of Nedd4 is mediated by an association of its C2 domain with the apically targeted annexin XIIIb.

scholarly journals c-Cbl Mediates Ubiquitination, Degradation, and Down-regulation of Human Protease-activated Receptor 2

2005 ◽  
Vol 280 (16) ◽  
pp. 16076-16087 ◽  
Author(s):  
Claire Jacob ◽  
Graeme S. Cottrell ◽  
Daphne Gehringer ◽  
Fabien Schmidlin ◽  
Eileen F. Grady ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Ring Finger ◽  
Dominant Negative ◽  
Dependent Manner ◽  
Wild Type ◽  
Lysosomal Degradation ◽  
Proteolytic Activation ◽  
Gpcr Signaling ◽  
Early Endosomes ◽  
Protease Activated Receptor 2

Mechanisms that arrest G-protein-coupled receptor (GPCR) signaling prevent uncontrolled stimulation that could cause disease. Although uncoupling from heterotrimeric G-proteins, which transiently arrests signaling, is well described, little is known about the mechanisms that permanently arrest signaling. Here we reported on the mechanisms that terminate signaling by protease-activated receptor 2 (PAR2), which mediated the proinflammatory and nociceptive actions of proteases. Given its irreversible mechanism of proteolytic activation, PAR2is a model to study the permanent arrest of GPCR signaling. By immunoprecipitation and immunoblotting, we observed that activated PAR2was mono-ubiquitinated. Immunofluorescence indicated that activated PAR2translocated from the plasma membrane to early endosomes and lysosomes where it was degraded, as determined by immunoblotting. Mutant PAR2lacking intracellular lysine residues (PAR2Δ14K/R) was expressed at the plasma membrane and signaled normally but was not ubiquitinated. Activated PAR2Δ14K/R internalized but was retained in early endosomes and avoided lysosomal degradation. Activation of wild type PAR2stimulated tyrosine phosphorylation of the ubiquitin-protein isopeptide ligase c-Cbl and promoted its interaction with PAR2at the plasma membrane and in endosomes in an Src-dependent manner. Dominant negative c-Cbl lacking the ring finger domain inhibited PAR2ubiquitination and induced retention in early endosomes, thereby impeding lysosomal degradation. Although wild type PAR2was degraded, and recovery of agonist responses required synthesis of new receptors, lysine mutation and dominant negative c-Cbl impeded receptor ubiquitination and degradation and allowed PAR2to recycle and continue to signal. Thus, c-Cbl mediated ubiquitination and lysosomal degradation of PAR2to irrevocably terminate signaling by this and perhaps other GPCRs.

Glycosylation of the osmoresponsive transient receptor potential channel TRPV4 on Asn-651 influences membrane trafficking

2006 ◽  
Vol 290 (5) ◽  
pp. F1103-F1109 ◽  
Author(s):  
Hongshi Xu ◽  
Yi Fu ◽  
Wei Tian ◽  
David M. Cohen
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Trp Channel ◽  
Hek293 Cells ◽  
Wild Type ◽  
Functional Feature ◽  
Voltage Gated ◽  
Transient Receptor

We identified a consensus N-linked glycosylation motif within the pore-forming loop between the fifth and sixth transmembrane segments of the osmoresponsive transient receptor potential (TRP) channel TRPV4. Mutation of this residue from Asn to Gln (i.e., TRPV4N651Q) resulted in loss of a slower migrating band on anti-TRPV4 immunoblots and a marked reduction in lectin-precipitable TRPV4 immunoreactivity. HEK293 cells transiently transfected with the mutant TRPV4N651Q exhibited increased calcium entry in response to hypotonic stress relative to wild-type TRPV4 transfectants. This increase in hypotonicity responsiveness was associated with an increase in plasma membrane targeting of TRPV4N651Q relative to wild-type TRPV4 in both HEK293 and COS-7 cells but had no effect on overall channel abundance in whole cell lysates. Residue N651 of TRPV4 is immediately adjacent to the pore-forming loop. Although glycosylation in this vicinity has not been reported for a TRP channel, the structurally related hexahelical hyperpolarization-activated cyclic nucleotide-gated channel, HCN2, and the voltage-gated potassium channel, human ether-a-go-go-related (HERG), share a nearly identically situated and experimentally confirmed N-linked glycosylation site which promotes rather than limits channel insertion into the plasma membrane. These data point to a potentially conserved structural and functional feature influencing membrane trafficking across diverse members of the voltage-gated-like ion channel superfamily.

scholarly journals Identification, localization, and functional implications of an abundant nematode annexin.

1996 ◽  
Vol 132 (6) ◽  
pp. 1079-1092 ◽  
Author(s):  
C E Creutz ◽  
S L Snyder ◽  
S N Daigle ◽  
J Redick
Keyword(s):  
Membrane Trafficking ◽  
Calcium Binding ◽  
Peptide Sequencing ◽  
Uterine Wall ◽  
Dependent Manner ◽  
Membrane Systems ◽  
Expression Library ◽  
Sequencing Project ◽  
Calcium Dependent ◽  
Chromosome Iii

Cultures of the nematode C. elegans were examined for the presence of calcium-dependent, phospholipid-binding proteins of the annexin class. A single protein of apparent mass on SDS-polyacrylamide gels of 32 kD was isolated from soluble extracts of nematode cultures on the basis of its ability to bind to phospholipids in a calcium-dependent manner. After verification of the protein as an annexin by peptide sequencing, an antiserum to the protein was prepared and used to isolate a corresponding cDNA from an expression library in phage lambda gt11. The encoded protein, herein referred to as the nex-1 annexin, has a mass of 35 kD and is 36-42% identical in sequence to 10 known mammalian annexins. Several unique modifications were found in the portions of the sequence corresponding to calcium-binding sites. Possible phosphorylation sites in the NH2-terminal domain of the nematode annexin correspond to those of mammalian annexins. The gene for this annexin (nex-1) was physically mapped to chromosome III in the vicinity of the dpy-17 genetic marker. Two other annexin genes (nex-2 and nex-3) were also identified in chromosome III sequences reported by the nematode genomic sequencing project (Sulston, J., Z. Du, K. Thomas, R. Wilson, L. Hillier, R. Staden, N. Halloran, P. Green, J. Thierry-Mieg, L. Qiu, et al. 1992. Nature (Lond.). 356:37-41). The nex-1 annexin was localized in the nematode by immunofluorescence and by electron microscopy using immunogold labeling. The protein is associated with membrane systems of the secretory gland cells of the pharynx, with sites of cuticle formation in the grinder in the pharynx, with yolk granules in oocytes, with the uterine wall and vulva, and with membrane systems in the spermathecal valve. The presence of the annexin in association with the membranes of the spermathecal valve suggests a novel function of the protein in the folding and unfolding of these membranes as eggs pass through the valve. The localizations also indicate roles for the annexin corresponding to those proposed in mammalian systems in membrane trafficking, collagen deposition, and extracellular matrix formation.

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