scholarly journals Structural Determinants in the Calcitonin Receptor-Like Receptor (Crlr) Important for Cgrp and Adrenomedullin (Am) Receptor Function of Crlr/Receptor-Activity-Modifying Protein (Ramp) 1 and Crlr/Ramp2 Heterodimers

2001 ◽  
Vol 1 ◽  
pp. 8-8
Author(s):  
W. Born ◽  
K. Leuthauser ◽  
R. Gujer ◽  
R. Muff ◽  
J.A. Fischer
Keyword(s):  
Cell Surface ◽  
Surface Protein ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Cross Linking ◽  
Cell Surface Protein ◽  
Calcitonin Receptor ◽  
Camp Production ◽  
Structural Determinants ◽  
Structural Alterations

Cell surface protein cross-linking, coimmmunoprecipitation, and confocal microscopy identified CRLR/RAMP1-, CRLR/RAMP2-, and calcitonin receptor isotype 2 (CTR2)/RAMP1 heterodimers as CGRP-, AM-, and CGRP/amylin receptors, linked to cAMP production. Along these lines, effects of structural alterations in the N-terminal extracellular domain of the human CRLR on cell surface expression as well as the association with RAMP and CGRP or AM have been investigated.

scholarly journals Signal peptide cleavage is essential for surface expression of a regulatory T cell surface protein, leucine rich repeat containing 32 (LRRC32)

2011 ◽  
Vol 12 (1) ◽  
pp. 27 ◽  
Author(s):  
Derek V Chan ◽  
Ally-Khan Somani ◽  
Andrew B Young ◽  
Jessica V Massari ◽  
Jennifer Ohtola ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
Signal Peptide ◽  
Regulatory T Cell ◽  
Surface Protein ◽  
Surface Expression ◽  
Cell Surface Protein ◽  
Leucine Rich Repeat ◽  
Peptide Cleavage

scholarly journals Involvement of LFA-1 in lymphoma invasion and metastasis demonstrated with LFA-1-deficient mutants.

1989 ◽  
Vol 108 (5) ◽  
pp. 1979-1985 ◽  
Author(s):  
F F Roossien ◽  
D de Rijk ◽  
A Bikker ◽  
E Roos
Keyword(s):  
Cell Surface ◽  
Surface Protein ◽  
Metastatic Potential ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Lymphocyte Function ◽  
Lymphoma Cells ◽  
Mutant Cells

Lymphocyte function-associated antigen-1 (LFA-1) is a leukocyte and lymphoma cell surface protein that promotes intercellular adhesion. We have previously shown that the invasion of hepatocyte cultures by lymphoma cells is inhibited by anti-LFA-1 antibodies (Roos, E., and F. F. Roossien. 1987. J. Cell Biol. 105:553-559). In addition, we now report that LFA-1 is also involved in invasion of lymphoma cells into fibroblast monolayers. To investigate the role of LFA-1 in metastasis of these lymphoma cells, we have generated mutants that are deficient in LFA-1 cell surface expression because of impaired synthesis of either the alpha or beta subunit precursor of LFA-1. We identified at least three distinct mutant clones. The invasive potential of the mutant cells in vitro, in both hepatocyte and fibroblast cultures, was considerably lower than that of parental cells. The metastatic potential of the mutants was much reduced, indicating that LFA-1 expression is required for efficient metastasis formation by certain lymphoma cells.

scholarly journals The Tetraspan Molecule Cd151, a Novel Constituent of Hemidesmosomes, Associates with the Integrin α6β4 and May Regulate the Spatial Organization of Hemidesmosomes

2000 ◽  
Vol 149 (4) ◽  
pp. 969-982 ◽  
Author(s):  
Lotus M.Th. Sterk ◽  
Cecile A.W. Geuijen ◽  
Lauran C.J.M. Oomen ◽  
Jero Calafat ◽  
Hans Janssen ◽  
...  
Keyword(s):  
Cell Surface ◽  
Spatial Organization ◽  
Transmembrane Domain ◽  
Focal Adhesions ◽  
Surface Protein ◽  
K562 Cells ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Junctional Epidermolysis Bullosa ◽  
Integrin Α6β4

CD151 is a cell surface protein that belongs to the tetraspan superfamily. It associates with other tetraspan molecules and certain integrins to form large complexes at the cell surface. CD151 is expressed by a variety of epithelia and mesenchymal cells. We demonstrate here that in human skin CD151 is codistributed with α3β1 and α6β4 at the basolateral surface of basal keratinocytes. Immunoelectron microscopy showed that CD151 is concentrated in hemidesmosomes. By immunoprecipitation from transfected K562 cells, we established that CD151 associates with α3β1 and α6β4. In β4-deficient pyloric atresia associated with junctional epidermolysis bullosa (PA-JEB) keratinocytes, CD151 and α3β1 are clustered together at the basal cell surface in association with patches of laminin-5. Focal adhesions are present at the periphery of these clusters, connected with actin filaments, and they contain both CD151 and α3β1. Transient transfection studies of PA-JEB cells with β4 revealed that the integrin α6β4 becomes incorporated into the α3β1-CD151 clusters where it induces the formation of hemidesmosomes. As a result, the amount of α3β1 in the clusters diminishes and the protein becomes restricted to the peripheral focal adhesions. Furthermore, CD151 becomes predominantly associated with α6β4 in hemidesmosomes, whereas its codistribution with α3β1 in focal adhesions becomes partial. The localization of α6β4 in the pre-hemidesmosomal clusters is accompanied by a strong upregulation of CD151, which is at least partly due to increased cell surface expression. Using β4 chimeras containing the extracellular and transmembrane domain of the IL-2 receptor and the cytoplasmic domain of β4, we found that for recruitment of CD151 into hemidesmosomes, the β4 subunit must be associated with α6, confirming that integrins associate with tetraspans via their α subunits. CD151 is the only tetraspan identified in hemidesmosomal structures. Others, such as CD9 and CD81, remain diffusely distributed at the cell surface. In conclusion, we show that CD151 is a major component of (pre)-hemidesmosomal structures and that its recruitment into hemidesmosomes is regulated by the integrin α6β4. We suggest that CD151 plays a role in the formation and stability of hemidesmosomes by providing a framework for the spatial organization of the different hemidesmosomal components.

scholarly journals Role of Asparagine-Linked Glycosylation in Cell Surface Expression and Function of the Human Adrenocorticotropin Receptor (Melanocortin 2 Receptor) in 293/FRT Cells

Endocrinology ◽  
2010 ◽  
Vol 151 (2) ◽  
pp. 660-670 ◽  
Author(s):  
Simon Roy ◽  
Benoît Perron ◽  
Nicole Gallo-Payet
Keyword(s):  
Cell Surface ◽  
Fold Increase ◽  
Surface Expression ◽  
Site Directed Mutagenesis ◽  
Cell Surface Receptor ◽  
Cell Surface Expression ◽  
Camp Production ◽  
Glycosylation Sites ◽  
Surface Receptor

Asparagine-linked glycosylation (N-glycosylation) of G protein-coupled receptors may be necessary for functions ranging from agonist binding, folding, maturation, stability, and internalization. Human melanocortin 2 receptor (MC2R) possesses putative N-glycosylation sites in its N-terminal extracellular domain; however, to date, the role of MC2R N-glycosylation has yet to be investigated. The objective of the present study is to examine whether N-glycosylation is essential or not for cell surface expression and cAMP production in native and MC2R accessory protein (MRAPα, -β, or -dCT)-expressing cells using 293/FRT transfected with Myc-MC2R. Western blot analyses performed with or without endoglycosidase H, peptide:N-glycosidase F or tunicamycin treatments and site-directed mutagenesis revealed that MC2R was glycosylated in the N-terminal domain at its two putative N-glycosylation sites (Asn12-Asn13-Thr14 and Asn17-Asn18-Ser19). In the absence of human MRAP coexpression, N-glycosylation of at least one of the two sites was necessary for MC2R cell surface expression. However, when MRAP was present, cell surface expression of MC2R mutants was either rescued entirely with the N17-18Q (QQNN) and N12-13Q (NNQQ) mutants or partially with the unglycosylated N12-13, 17-18Q (QQQQ) mutant. Functional and expression analyses revealed a discrepancy between wild-type (WT) and QQQQ cell surface receptor levels and maximal cAMP production with a 4-fold increase in EC50 values. Taken together, these results indicate that the absence of MC2R N-glycosylation abrogates to a large extent MC2R cell surface expression in the absence of MRAPs, whereas when MC2R is N-glycosylated, it can be expressed at the plasma membrane without MRAP assistance.

scholarly journals Structural determinants regulating cell surface targeting of melanocortin receptors

2013 ◽  
Vol 51 (2) ◽  
pp. R23-R32 ◽  
Author(s):  
A R Rodrigues ◽  
D Sousa ◽  
H Almeida ◽  
A M Gouveia
Keyword(s):  
Cell Surface ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Melanocortin Receptors ◽  
Control Mechanisms ◽  
Structural Determinants ◽  
Surface Integration ◽  
C Terminus ◽  
G Protein Coupled

Melanocortin receptors (MCRs) belong to the G-protein-coupled receptor family of transmembrane proteins. They recognize specific ligands named melanocortins that are mainly produced in the pituitary and hypothalamus. Newly synthesized MCRs at the endoplasmic reticulum are subjected to quality control mechanisms that screen for the correct structure, folding or processing, essential for their proper cell surface expression. Some motifs, located at the N- or C-terminus or even on transmembrane and in loop regions, have been implicated in these biological processes. This article reviews these specific domains and the role of accessory proteins and post-translation modifications in MCRs' targeting to cell surface. Additionally, promising approaches involving pharmacological stabilization of misfolded and misrouted mutant MCRs, which improve their forward transport, are reported. Understanding the MCRs' structural determinants fundamental for their proper cell surface integration is essential for correcting abnormalities found in some diseases.

scholarly journals Trafficking of Kv1.4 potassium channels: interdependence of a pore region determinant and a cytoplasmic C-terminal VXXSL determinant in regulating cell-surface trafficking

2003 ◽  
Vol 375 (3) ◽  
pp. 761-768 ◽  
Author(s):  
Jing ZHU ◽  
Itaru WATANABE ◽  
Barbara GOMEZ ◽  
William B. THORNHILL
Keyword(s):  
Cell Surface ◽  
Cell Function ◽  
Cell Signalling ◽  
Surface Protein ◽  
Surface Expression ◽  
Inhibitory Effect ◽  
Cell Surface Expression ◽  
Pore Region ◽  
Expression Levels ◽  
Protein Levels

Kv1.4 and Kv1.1 potassium channel homomers have been shown to exhibit different intracellular trafficking programmes and cell-surface expression levels in cell lines: a determinant in the pore region of Kv1.4 and Kv1.1 [Zhu, Watanabe, Gomez and Thornhill (2001) J. Biol. Chem. 276, 39419–39427] and a cytoplasmic C-terminal VXXSL determinant on Kv1.4 [Li, Takimoto and Levitan (2000) J. Biol. Chem. 275, 11597–11602] have been described, which affected trafficking and cell-surface expression levels. In the present study, we examined whether trafficking pore determinants influenced any cytoplasmic C-terminal trafficking determinant. We found that removal of VXXSL from a Kv1.4 chimaera that contained the pore of Kv1.1 did not affect cell-surface trafficking. Therefore removal of the C-terminal VXXSL of Kv1.4 inhibited protein surface levels only in the presence of the Kv1.4 pore. In contrast, truncating the cytoplasmic C-terminus of Kv1.1 or truncating a Kv1.1 chimaera with the pore of Kv1.4, had little effect on surface protein levels. Furthermore, the subregion of the Kv1.4 pore trafficking determinant that was required for the inhibitory effect of VXXSL removal was mapped to a threonine residue in the deep pore region. Therefore the Kv1.4 pore determinant affected the trafficking and cell-surface levels directed by the C-terminal VXXSL determinant. Different Kv1 trafficking programmes would affect cell-surface expression levels either positively or negatively and also cell signalling. Cells may use differential trafficking programmes of membrane proteins as a post-translational mechanism to regulate surface protein levels and cell function.

scholarly journals Glycosylation of the calcitonin receptor-like receptor at Asn60 or Asn112 is important for cell surface expression

FEBS Letters ◽  
2000 ◽  
Vol 486 (3) ◽  
pp. 320-324 ◽  
Author(s):  
Nicole Bühlmann ◽  
Amaya Aldecoa ◽  
Kerstin Leuthäuser ◽  
Remo Gujer ◽  
Roman Muff ◽  
...  
Keyword(s):  
Cell Surface ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Calcitonin Receptor

The activation of the CGRP receptor

2013 ◽  
Vol 41 (1) ◽  
pp. 180-184 ◽  
Author(s):  
James Barwell ◽  
Mark Wheatley ◽  
Alex C. Conner ◽  
Bruck Taddese ◽  
Shabana Vohra ◽  
...  
Keyword(s):  
Cell Surface ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Accessory Protein ◽  
Calcitonin Receptor ◽  
Cgrp Receptor ◽  
Peptide Receptor ◽  
Calcitonin Gene ◽  
New Knowledge ◽  
G Protein Coupled

The CGRP (calcitonin gene-related peptide) receptor is a family B GPCR (G-protein-coupled receptor). It consists of a GPCR, CLR (calcitonin receptor-like receptor) and an accessory protein, RAMP1 (receptor activity modifying protein 1). RAMP1 is needed for CGRP binding and also cell-surface expression of CLR. CLR is an example of a family B GPCR. Unlike family A GPCRs, little is known about how these receptors are activated by their endogenous ligands. This review considers what is known about the activation of family B GPCRs and then considers how this might be applied to CLR, particularly in light of new knowledge of the crystal structures of family A GPCRs.

scholarly journals Cross-linking of neutrophil CD11b results in rapid cell surface expression of molecules required for antigen presentation and T-cell activation

Immunology ◽  
2005 ◽  
Vol 114 (3) ◽  
pp. 354-368 ◽  
Author(s):  
Gavin P. Sandilands ◽  
Zubir Ahmed ◽  
Nicole Perry ◽  
Martin Davison ◽  
Alison Lupton ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
Antigen Presentation ◽  
T Cell Activation ◽  
Cell Activation ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Cross Linking
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