scholarly journals Isoforms of Ankyrin-3 That Lack the NH2-terminal Repeats Associate with Mouse Macrophage Lysosomes

1997 ◽  
Vol 136 (5) ◽  
pp. 1059-1070 ◽  
Author(s):  
Thomas C. Hoock ◽  
Luanne L. Peters ◽  
Samuel E. Lux
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Endocytic Pathway ◽  
Cdna Clones ◽  
Mouse Macrophage ◽  
Regulatory Domains ◽  
Binding Domains ◽  
Mouse Macrophages ◽  
Repeat Domain ◽  
Terminal Repeats

We have recently cloned and characterized ankyrin-3 (also called ankyrinG), a new ankyrin that is widely distributed, especially in epithelial tissues, muscle, and neuronal axons (Peters, L.L., K.M. John, F.M. Lu, E.M. Eicher, A. Higgins, M. Yialamas, L.C. Turtzo, A.J. Otsuka, and S.E. Lux. 1995. J. Cell Biol. 130: 313–330). Here we show that in mouse macrophages, ankyrin-3 is expressed exclusively as two small isoforms (120 and 100 kD) that lack the NH2-terminal repeats. Sequence analysis of isolated Ank3 cDNA clones, obtained by reverse transcription and amplification of mouse macrophage RNA (GenBank Nos. U89274 and U89275), reveals spectrin-binding and regulatory domains identical to those in kidney ankyrin-3 (GenBank No. L40631) preceded by a 29–amino acid segment of the membrane (“repeat”) domain, beginning near the end of the last repeat. Antibodies specific for the regulatory and spectrin-binding domains of ankyrin-3 localize the protein to the surface of intracellular vesicles throughout the macrophage cytoplasm. It is not found on the plasma membrane. Also, epitope-tagged mouse macrophage ankyrin-3, transiently expressed in COS cells, associates with intracellular, not plasma, membranes. In contrast, ankyrin-1 (erythrocyte ankyrin, ankyrinR), which is also expressed in mouse macrophages, is located exclusively on the plasma membrane. The ankyrin-3–positive vesicles appear dark on phasecontrast microscopy. Two observations suggest that they are lysosomes. First, they are a late compartment in the endocytic pathway. They are only accessible to a fluorescent endocytic tracer (FITC-dextran) after a 24-h incubation, at which time all of the FITC-dextran– containing vesicles contain ankyrin-3 and vice versa. Second, the ankyrin-3–positive vesicles contain lysosomal-associated membrane glycoprotein (LAMP-1), a recognized lysosomal marker. This is the first evidence for the association of an ankyrin with lysosomes and is an example of two ankyrins present in the same cell that segregate to different locations.

Structural diversity of band 4.1 superfamily members

1994 ◽  
Vol 107 (7) ◽  
pp. 1921-1928 ◽  
Author(s):  
K. Takeuchi ◽  
A. Kawashima ◽  
A. Nagafuchi ◽  
S. Tsukita
Keyword(s):  
Plasma Membrane ◽  
Tyrosine Kinases ◽  
Plasma Membranes ◽  
Structural Diversity ◽  
Gene Families ◽  
Cdna Clones ◽  
New Members ◽  
F9 Cells ◽  
Novel Proteins ◽  
Cellular Events

Several proteins contain the domain homologous to the N-terminal half of band 4.1 protein, indicating the existence of a superfamily. The members of this ‘band 4.1’ superfamily are thought to play crucial roles in the regulation of cytoskeleton-plasma membrane interaction just beneath plasma membranes. We examined the structural diversity of this superfamily by means of the polymerase chain reaction using synthesized mixed primers. We thus identified many members of the band 4.1 superfamily that were expressed in mouse teratocarcinoma F9 cells and mouse brain tissue. In total, 15 cDNA clones were obtained; 8 were identical to the corresponding parts of cDNAs for the known members, while 7 appeared to encode novel proteins (NBL1-7: novel band 4.1-like proteins). Sequence analyses of these clones revealed that the band 4.1 superfamily can be subdivided into 5 gene families; band 4.1 protein, ERM (ezrin/radixin/moesin/merlin/NBL6/NBL7+ ++), talin, PTPH1 (PTPH1/PTPMEG/NBL1-3), and NBL4 (NBL4/NBL5) families. The NBL4 family was first identified here, and the full-length cDNA encoding NBL4 was cloned. The deduced amino acid sequence revealed a myristoylation site, as well as phosphorylation sites for A-kinase and tyrosine kinases in its N-terminal half, suggesting its involvement in the phosphorylation-dependent regulation of cellular events just beneath the plasma membrane. In this study, we describe the initial characterization of these new members and discuss the evolution of the band 4.1 superfamily.

scholarly journals The VE-cadherin cytoplasmic domain undergoes proteolytic processing during endocytosis

2017 ◽  
Vol 28 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Wenji Su ◽  
Andrew P. Kowalczyk
Keyword(s):  
Plasma Membrane ◽  
Adhesion Strength ◽  
Turnover Rate ◽  
Cytoplasmic Tail ◽  
Cytoplasmic Domain ◽  
Proteolytic Processing ◽  
Endocytic Pathway ◽  
Cytoplasmic Domains ◽  
P120 Catenin ◽  
Binding Domains

VE-cadherin trafficking to and from the plasma membrane has emerged as a critical mechanism for regulating cadherin surface levels and adhesion strength. In addition, proteolytic processing of cadherin extracellular and cytoplasmic domains has been reported to regulate cadherin adhesion and signaling. Here we provide evidence that VE-cadherin is cleaved by calpain upon entry into clathrin-enriched domains. This cleavage event occurs between the β-catenin and p120-binding domains within the cadherin cytoplasmic tail. Of interest, VE-cadherin mutants that are resistant to endocytosis are similarly resistant to cleavage. Furthermore, p120-catenin overexpression blocks cadherin internalization and cleavage, coupling entry into the endocytic pathway with proteolytic processing. Of importance, the cleavage of the VE-cadherin tail alters the postendocytic trafficking itinerary of the cadherin, resulting in a higher turnover rate due to decreased recycling and increased degradation. In conclusion, this study identifies a novel proteolytic event that regulates the trafficking of VE-cadherin after endocytosis.

scholarly journals cDNA cloning reveals the molecular structure of a sperm surface protein, PH-20, involved in sperm-egg adhesion and the wide distribution of its gene among mammals.

1990 ◽  
Vol 111 (6) ◽  
pp. 2939-2949 ◽  
Author(s):  
W F Lathrop ◽  
E P Carmichael ◽  
D G Myles ◽  
P Primakoff
Keyword(s):  
Plasma Membrane ◽  
Guinea Pig ◽  
Zona Pellucida ◽  
Genomic Dna ◽  
Surface Protein ◽  
Wide Distribution ◽  
Cdna Clones ◽  
Southern Blots ◽  
Binding Domains ◽  
Acrosomal Membrane

Sperm binding to the egg zona pellucida in mammals is a cell-cell adhesion process that is generally species specific. The guinea pig sperm protein PH-20 has a required function in sperm adhesion to the zona pellucida of guinea pig eggs. PH-20 is located on both the sperm plasma membrane and acrosomal membrane. We report here the isolation and sequence of a full-length cDNA for PH-20 (available from EMBL/GenBank/DDBJ under accession number X56332). The derived amino acid sequence shows a mature protein of 468 amino acids containing six N-linked glycosylation sites and twelve cysteines, eight of which are tightly clustered near the COOH terminus. The sequence indicates PH-20 is a novel protein with no relationship to the mouse sperm adhesion protein galactosyl transferase and no significant homology with other known proteins. The two PH-20 populations, plasma membrane and acrosomal membrane, could arise because one form of PH-20 is encoded and differentially targeted at different spermatogenic stages. Alternatively, two different forms of PH-20 could be encoded. Our evidence thus far reveals only one sequence coding for PH-20: Southern blots of guinea pig genomic DNA indicated there is a single PH-20 gene, Northern blots showed a single size PH-20 message (approximately 2.2 kb), and no sequence variants were found among the sequenced cDNA clones. Cross-species Southern blots reveal the presence of a homologue of the PH-20 gene in mouse, rat, hamster, rabbit, bovine, monkey, and human genomic DNA, showing the PH-20 gene is conserved among mammals. Since genes for zona glycoproteins are also conserved among mammals, the general features of sperm and zona proteins involved in mammalian sperm-egg adhesion may have been evolutionarily maintained. Species specificity may result from limited changes in these molecules, either in their binding domains or in other regions that affect the ability of the binding domains to interact.

scholarly journals Transcytosis via the late endocytic pathway as a cell morphogenetic mechanism

2020 ◽  
Author(s):  
R Mathew ◽  
LD Rios-Barrera ◽  
P Machado ◽  
Y Schwab ◽  
M Leptin
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Basal Membrane ◽  
Endocytic Pathway ◽  
Apical Plasma Membrane ◽  
Tracheal System ◽  
Basal Plasma ◽  
Membrane Compartments ◽  
Membrane Growth ◽  
A Cell

AbstractPlasma membranes fulfil many physiological functions. In polarized cells, different membrane compartments take on specialized roles, each being allocated correct amounts of membrane. The Drosophila tracheal system, an established tubulogenesis model, contains branched terminal cells with subcellular tubes formed by apical plasma membrane invagination. We show that apical endocytosis and late endosome-mediated trafficking determine the membrane allocation to the apical and basal membrane domains. Basal plasma membrane growth stops if endocytosis is blocked, whereas the apical membrane grows excessively. Plasma membrane is initially delivered apically, and then continuously endocytosed, together with apical and basal cargo. We describe an organelle carrying markers of late endosomes and multivesicular bodies (MVBs) that is abolished by inhibiting endocytosis, and which we suggest acts as transit station for membrane destined to be redistributed both apically and basally. This is based on the observation that disrupting MVB formation prevents growth of both compartments.

scholarly journals SEGMENTAL RESPONSE OF THE MACROPHAGE PLASMA MEMBRANE TO A PHAGOCYTIC STIMULUS

1974 ◽  
Vol 139 (2) ◽  
pp. 323-336 ◽  
Author(s):  
Frank M. Griffin ◽  
Samuel C. Silverstein
Keyword(s):  
Plasma Membrane ◽  
Cell Types ◽  
Mouse Macrophage ◽  
Latex Particles ◽  
Mouse Macrophages ◽  
Cross Linkage

A method of attaching mouse RBCs to mouse macrophages is described. Both cell types were coated with rabbit anti-mouse macrophage F(ab')2, and cross-linkage of cells was effected with sheep F(ab')2 directed against rabbit F(ab')2. 98% of macrophages attached an average of 11 RBCs each. Attachment occurred at 37°C and was stable for at least 4 h. Less than 0.1% of macrophages ingested RBCs under these conditions. Latex particles and opsonized pneumococci were ingested as avidly by RBC-coated macrophages as by native macrophages. Ingestion of these particles did not prompt ingestion of attached RBCs. When anti-RBC IgG was added, however, over 90% of macrophages ingested an average of six RBCs each. Thus, ingestion of one particle does not trigger generalized phagocytosis of all particles attached to the cell's plasma membrane, and the phagocytic stimulus is confined to the segment of the cell's plasma membrane immediately adjacent to the particle being ingested.

scholarly journals COPI mediates recycling of an exocytic SNARE by recognition of a ubiquitin sorting signal

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Peng Xu ◽  
Hannah M Hankins ◽  
Chris MacDonald ◽  
Samuel J Erlinger ◽  
Meredith N Frazier ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Golgi Complex ◽  
Endocytic Pathway ◽  
Endocytic Trafficking ◽  
Degradative Pathway ◽  
Binding Domains ◽  
Transport Vesicles ◽  
Ubiquitin Binding ◽  
Target Membrane

The COPI coat forms transport vesicles from the Golgi complex and plays a poorly defined role in endocytic trafficking. Here we show that COPI binds K63-linked polyubiquitin and this interaction is crucial for trafficking of a ubiquitinated yeast SNARE (Snc1). Snc1 is a v-SNARE that drives fusion of exocytic vesicles with the plasma membrane, and then recycles through the endocytic pathway to the Golgi for reuse in exocytosis. Removal of ubiquitin from Snc1, or deletion of a β'-COP subunit propeller domain that binds K63-linked polyubiquitin, disrupts Snc1 recycling causing aberrant accumulation in internal compartments. Moreover, replacement of the β'-COP propeller domain with unrelated ubiquitin-binding domains restores Snc1 recycling. These results indicate that ubiquitination, a modification well known to target membrane proteins to the lysosome or vacuole for degradation, can also function as recycling signal to sort a SNARE into COPI vesicles in a non-degradative pathway.

scholarly journals Phosphatidylinositol phosphate binding domains exhibit complex dissociation properties at the inner leaflet of plasma membrane sheets

2021 ◽  
Author(s):  
Madeline R. Sponholtz ◽  
Eric N. Senning
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
High Specificity ◽  
Ph Domain ◽  
Phosphate Binding ◽  
Dissociation Kinetics ◽  
Binding Domains ◽  
Phosphatidylinositol Phosphate ◽  
Gfp Fluorescence ◽  
Associated Proteins

AbstractThe pleckstrin homology (PH) domain is a lipid targeting motif that binds with high specificity to phosphatidylinositol phosphate (PIP) lipids. Using TIRF microscopy, we followed the dissociation of GFP-tagged PH domains from the plasma membranes of rapidly unroofed cells and found that AKT-PH and PLCδ1-PH dissociation kinetics can be distinguished by their effective koff values determined from fitting fluorescence traces to a single exponential equation. Our measurements for the koff of AKT-PH-GFP and PLCδ1-PH-GFP were significantly different (p < 0.05) at 0.39 ± 0.05 s−1 and 0.56 ± 0.17 s−1, respectively. Furthermore, we identified substantial rebinding events in our measurements of PLCδ1-PH-GFP dissociation kinetics. By applying inositol triphosphate (IP3) to samples during the unroofing process, we measured a much faster koff of 1.54 ± 0.42 s−1 for PLCδ1-PH-GFP, indicating that rebinding events are significantly depressed through competitive action by IP3 for the same PH domain binding site as phosphatidylinositol (4,5)-bisphosphate (PIP2). We discuss the complex character of our PLCδ1-PH-GFP fluorescence decays in the context of membrane receptor and ligand theory to address the question of how free PIP2 levels modulate the interaction between membrane associated proteins and the plasma membrane.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

Pore-Spanning Plasma Membranes Derived from Giant Plasma Membrane Vesicles

2021 ◽  
Author(s):  
Nikolas K. Teiwes ◽  
Ingo Mey ◽  
Phila C. Baumann ◽  
Lena Strieker ◽  
Ulla Unkelbach ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Membrane Vesicles ◽  
Plasma Membrane Vesicles
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