Endocytosis

The regulator of ubiquitous kinase (Ruk) protein, also known as CIN85 or SETA, is an adaptor-type protein belonging to the CD2AP/CMS family. It was found in complexes with many signaling proteins, including phos1 phoinositol (PtdIns) 3-kinase (EC 2.7.1.137), Cbl, GRB2, p130Cas and Crk. Functional analysis of these interactions, implicated Ruk in the regulation of apoptosis, receptor endocytosis and cytoskeletal rearrangements.

7p research12 01-06-2013 27 4   Download

In late larvae of the blowfly, Calliphora vicina, arylphorin and LSP-2 proteins, which belong to the class of hexamerins, are selectively taken up by the fat body from the haemolymph. Hexamerin endocytosis is mediated by a specific membranebound receptor, the arylphorin-binding protein (ABP). Using the two-hybrid technique, we found that the anterior fat body protein (AFP) interacts with the hexamerin receptor.

7p research12 01-06-2013 32 4   Download

a2 -Macroglobulin (a2M) is an abundant glycoprotein with the intrinsic capacity for capturing diverse proteins for rapid delivery into cells. After internalization by the receptor-mediated endocytosis,a2M-protein complexes were rapidly degraded in the endolysosome system. Although this is an importantpathway for clearanceofbotha2Mandbiological targets, little is known about the nature ofa2M degradation in the endolysosome system.

10p tumor12 20-04-2013 33 3   Download

Several protein toxins, such as the potent plant toxin ricin, enter mamma-lian cells by endocytosis and undergo retrograde transport via the Golgi complex to reach the endoplasmic reticulum (ER). In this compartment the catalytic moieties exploit the ER-associated degradation (ERAD) pathway to reach their cytosolic targets. Bacterial toxins such as cholera toxin or Pseudomonasexotoxin A carry KDEL or KDEL-like C-terminal tetrapep-tides for efficient delivery to the ER.

13p fptmusic 12-04-2013 45 3   Download

Shiga toxin can be internalized by clathrin-dependent endocytosis in differ-ent cell lines, although it binds specifically to the glycosphingolipid Gb3. It has been demonstrated previously that the toxin can induce recruitment of the toxin–receptor complex to clathrin-coated pits, but whether this process is concentration-dependent or which part of the toxin molecule is involved in this process, have so far been unresolved issues.

11p fptmusic 11-04-2013 50 2   Download

Rabaptin-5 is an effector for the small GTPase Rab5, a regulator of the early steps in endocytosis. In addition, Rabaptin-5 interacts with the small GTPase Rab4 that has been implicated in recycling from early endosomes to the cell surface. Recently we have identified a ubiquitous transcript encoding the Rabaptin-5 isoform, Rabaptin-5d. To evaluate the interaction properties of Rabaptin-5d with the small GTPases Rab4 and Rab5, we have applied protein interaction assays using the yeast two-hybrid system and a glutathione S-transferase pull-down assay. ...

0p awards 05-04-2013 35 3   Download

Lactoferrin (Lf), a multifunctional molecule present in mammalian secretions and blood, plays important roles in host defense and cancer. Indeed, Lf has been reported to inhibit the proliferation of cancerous mammary gland epi-thelial cells and manifest a potent antiviral activity against human immunodeficiency virus and human cytomegalo-virus. The Lf-binding sites on the cell surface appear to be proteoglycans and other as yet undefined protein(s).

15p dell39 03-04-2013 46 5   Download

Dynamin, a protein playing crucial roles in endocytosis, oligomerizes to form spirals around the necks of incipient vesicles and helps their scission from membranes. This oligomerization is known to be mediated by the GTPase effector domain (GED). Here we have characterized the structural features of recombinant GED using a variety of biophysical methods.

10p dell39 27-03-2013 38 3   Download

During vitellogenesis, one of the most tightly regulated processes in ovipar-ous reproduction, vitellogenins are incorporated into the oocyte through vitellogenin receptor (VgR)-mediated endocytosis. In this paper, we report the cloning of the VgR cDNA from Blattella germanica, as well as the first functional analysis of VgR following an RNA interference (RNAi) approach.

11p dell39 27-03-2013 40 1   Download

Some endocytosis receptors related to the low-density lipoprotein receptor, including low-density lipoprotein receptor-related protein-1A, very-low-density lipoprotein receptor, and sorting protein-related receptor, bind pro-tease-inhibitor complexes, including urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and the uPA–PAI-1 com-plex.

17p inspiron33 23-03-2013 43 3   Download

It has been demonstrated that the plasma membrane expression of ZIP1 is regulated by endocytic mechanisms. In the zinc-replete condition, the level of surface expressed ZIP1 is low due to the rapid internalization of ZIP1. The present study aimed to identify a sorting signal(s) in ZIP1 that medi-ated endocytosis of ZIP1.

12p galaxyss3 21-03-2013 39 5   Download

Using thein situ liver model system, we have recently shown that, after cholera toxin binding to hepatic cells, cholera toxin accumulates in a low-density endosomal compartment, and then undergoes endosomal proteoly-sis by the aspartic acid protease cathepsin-D [Merlen C, Fayol-Messaoudi D, Fabrega S, El Hage T, Servin A, Authier F (2005)FEBS J272, 4385– 4397]. Here, we have used a subcellular fractionation approach to address the in vivo compartmentalization and cytotoxic action of cholera toxin in rat liver parenchyma....

16p galaxyss3 21-03-2013 55 4   Download

Recurrent missense fibroblast growth factor receptor 3 (FGFR3) mutations have been ascribed to skeletal dysplasias of variable severity including the lethal neonatal thanatophoric dysplasia types I (TDI) and II (TDII). To elucidate the role of activating mutations causing TDI on receptor traffick-ing and endocytosis, a series of four mutants located in different domains of the receptor were generated and transiently expressed.

11p galaxyss3 19-03-2013 36 4   Download

Somatostatin receptor (SSTR) endocytosis influences cellular responsiveness to agonist stimulation and somatostatin receptor scintigraphy, a common diagnostic imaging technique. Recently, we have shown that SSTR1 is dif-ferentially regulated in the endocytic and recycling pathway of pancreatic cells after agonist stimulation.

12p galaxyss3 07-03-2013 28 5   Download

The insect low-density lipoprotein (LDL) receptor (LDLR) homolog, lipo-phorin receptor (LpR), mediates endocytic uptake of the single insect lipo-protein, high-density lipophorin (HDLp), which is structurally related to LDL. However, in contrast to the fate of LDL, which is endocytosed by LDLR, we previously demonstrated that after endocytosis, HDLp is sorted to the endocytic recycling compartment and recycled for resecretion in a transferrin-like manner.

16p media19 06-03-2013 30 3   Download

A detailed proteolysis study of internalized diphtheria toxin (DT) within rat liver endosomes was undertaken to determine whether DT-resistant species exhibit defects in toxin endocytosis, toxin activation by cellular enzymes or toxin translocation to its cytosolic target.

15p media19 06-03-2013 36 2   Download

Ricin is a heterodimeric plant protein that is potently toxic to mammalian cells. Toxicity results from the catalytic depurination of eukaryotic ribo-somes by ricin toxin A chain (RTA) tBáo cáo khoa học: The isolation and characterization of temperature-dependehat follows toxin endocytosis to, and translocation across, the endoplasmic reticulum membrane.

14p media19 04-03-2013 52 3   Download

Notch ligands are membrane-spanning proteins made of a large extracellu-lar region, a transmembrane segment, and a 100–200 residue cytoplasmic tail. The intracellular region of Jagged-1, one of the five ligands to Notch receptors in man, mediates protein–protein interactions through the C-ter-minal PDZ binding motif, is involved in receptor⁄ligand endocytosis trig-gered by mono-ubiquitination,

12p media19 04-03-2013 22 1   Download

Vrp1p (verprolin, End5p) is the yeast ortholog of human Wiskott–Aldrich syndrome protein (WASP)-interacting protein (WIP). Vrp1p localizes to the cortical actin cytoskeleton, is necessary for its polarization to sites of growth and is also essential for endocytosis. At elevated temperature, Vrp1p becomes essential for growth.

23p media19 04-03-2013 36 4   Download

Gangliosides are glycosphingolipids mainly present at the outer leaflet of the plasma membrane of eukaryotic cells, where they participate in recogni-tion and signalling activities. The synthesis of gangliosides is carried out in the lumen of the Golgi apparatus by a complex system of glycosyltrans-ferases.

14p vinaphone15 28-02-2013 41 3   Download