Role of cell-surface receptors in the behaviour in vivo of transferren

Integrins are cell surface receptors that bind cells to their physical external environment, linking the extracellular matrix to cell function. They are essential in the biology of all animals. In the late 1980s, we discovered that integrins are required for the ability of breast epithelia to do what they are programmed to do, which is to differentiate and make milk. Since then, integrins have been shown to control most other aspects of phenotype: to stay alive, to divide, and to move about. Integrins also provide part of the mechanism that allows cells to form tissues. Here I discuss how we discovered that integrins control mammary gland differentiation and explore the role of integrins as central architects of other aspects of cell behavior.

Download Full-text

Ultraviolet irradiation rapidly activates cell surface receptors and three distinct map kinase modules in human skin in vivo

Journal of Dermatological Science ◽

10.1016/s0923-1811(98)83010-7 ◽

1998 ◽

Vol 16 ◽

pp. S2

Author(s):

JY Lin ◽

YS Wan ◽

Z Bata-Csorgo ◽

HS Talwar ◽

S Kang ◽

...

Keyword(s):

Cell Surface ◽

Map Kinase ◽

Human Skin ◽

Ultraviolet Irradiation ◽

Cell Surface Receptors ◽

Surface Receptors

Download Full-text

Differential Regulation of the Uridine Nucleotide-activated P2Y4 and P2Y6 Receptors

Journal of Biological Chemistry ◽

10.1074/jbc.m009909200 ◽

2000 ◽

Vol 276 (15) ◽

pp. 11939-11948 ◽

Cited By ~ 47

Author(s):

Amy E. Brinson ◽

T. Kendall Harden

Keyword(s):

Cell Surface ◽

Inositol Phosphate ◽

Complete Recovery ◽

Differential Regulation ◽

Cell Surface Receptors ◽

Surface Receptors ◽

Astrocytoma Cells ◽

Truncation Mutant ◽

Uridine Nucleotide

Agonist-promoted regulation of the uridine nucleotide-activated human P2Y4 receptor (P2Y4-R) and P2Y6 receptor (P2Y6-R) was studied. Incubation of P2Y4-R-expressing 1321N1 human astrocytoma cells with the cognate agonist UTP resulted in rapid desensitization of the inositol phosphate response and a 50% loss of cell surface receptors. In contrast, incubation of P2Y6-R-expressing cells with the cognate agonist UDP caused neither rapid desensitization nor rapid loss of cell surface receptors. Removal of UTP from the medium of UTP-pretreated cells resulted in rapid and complete recovery of surface P2Y4-R even after 12 h of agonist treatment. Although extended incubation with UDP also caused a loss of surface P2Y6-R, rapid recovery of surface P2Y6-R did not occur following removal of agonist. Pharmacological studies indicated that neither protein kinase C nor other Ca2+-activated kinases were involved in agonist-promoted desensitization or loss of surface P2Y4-R or P2Y6-R. Mutational analyses were carried out to identify domains involved in agonist-dependent regulation of P2Y4-R. Sequential truncation of the carboxyl-terminal domain revealed that sequence between amino acids 332 and 343 was necessary for UTP-promoted desensitization and internalization. Further mutational analyses of the three serines in this domain confirmed that Ser-333 and Ser-334 play a major role in these agonist-promoted changes in P2Y4-R. Experiments were carried out with [32P]Pi-labeled cells to ascertain the role of phosphorylation in regulation of P2Y4-R. Incubation with UTP for 2 min caused a marked increase in phosphorylation of both the wild-type P2Y4-R and the P2Y4–343 truncation mutant. In contrast, no UTP-promoted phosphorylation of the P2Y4–332 truncation mutant was observed. Taken together, these results demonstrate differential regulation of uridine nucleotide-activated P2Y4-R and P2Y6-R and indicate that Ser-333 and Ser-334 in the carboxyl terminus of P2Y4-R are important for UTP-dependent phosphorylation, desensitization, and loss of surface receptors.

Download Full-text

In vivo quantification of cell-surface receptors in solid cancers: two imaging agents are better than one

Optics in the Life Sciences ◽

10.1364/boda.2015.bt4a.2 ◽

2015 ◽

Author(s):

Kenneth M. Tichauer

Keyword(s):

Cell Surface ◽

Imaging Agents ◽

Cell Surface Receptors ◽

Surface Receptors ◽

Better Than

Download Full-text

Redirecting Retroviral Tropism by Insertion of Short, Nondisruptive Peptide Ligands into Envelope

Journal of Virology ◽

10.1128/jvi.76.7.3558-3563.2002 ◽

2002 ◽

Vol 76 (7) ◽

pp. 3558-3563 ◽

Cited By ~ 22

Author(s):

Timothy J. Gollan ◽

Michael R. Green

Keyword(s):

Cell Surface ◽

Leukemia Virus ◽

Envelope Proteins ◽

Peptide Ligands ◽

Viral Envelope ◽

Moloney Murine Leukemia Virus ◽

Cell Surface Receptors ◽

Wild Type ◽

Surface Receptors

ABSTRACT A potentially powerful approach for in vivo gene delivery is to target retrovirus to specific cells through interactions between cell surface receptors and appropriately modified viral envelope proteins. Previously, relatively large (>100 residues) protein ligands to cell surface receptors have been inserted at or near the N terminus of retroviral envelope proteins. Although viral tropism could be altered, the chimeric envelope proteins lacked full activity, and coexpression of wild-type envelope was required for production of transducing virus. Here we analyze more than 40 derivatives of ecotropic Moloney murine leukemia virus (MLV) envelope, containing insertions of short RGD-containing peptides, which are ligands for integrin receptors. In many cases pseudotyped viruses containing only the chimeric envelope protein could transduce human cells. The precise location, size, and flanking sequences of the ligand affected transduction specificity and efficiency. We conclude that retroviral tropism can be rationally reengineered by insertion of short peptide ligands and without the need to coexpress wild-type envelope.

Download Full-text

Sulfated polysaccharides identified as inducers of neuropilin-1 internalization and functional inhibition of VEGF165 and semaphorin3A

Blood ◽

10.1182/blood-2007-09-112474 ◽

2008 ◽

Vol 111 (8) ◽

pp. 4126-4136 ◽

Cited By ~ 37

Author(s):

Masashi Narazaki ◽

Marta Segarra ◽

Giovanna Tosato

Keyword(s):

Cell Surface ◽

Dextran Sulfate ◽

Receptor Internalization ◽

Sulfated Polysaccharides ◽

Cell Surface Receptors ◽

Ligand Interaction ◽

Surface Receptors ◽

Neuropilin 1

Abstract Neuropilin-1 (NRP1) and NRP2 are cell surface receptors shared by class 3 semaphorins and vascular endothelial growth factor (VEGF). Ligand interaction with NRPs selects the specific signal transducer, plexins for semaphorins or VEGF receptors for VEGF, and promotes NRP internalization, which effectively shuts down receptor-mediated signaling by a second ligand. Here, we show that the sulfated polysaccharides dextran sulfate and fucoidan, but not others, reduce endothelial cell-surface levels of NRP1, NRP2, and to a lesser extent VEGFR-1 and VEGFR-2, and block the binding and in vitro function of semaphorin3A and VEGF165. Administration of fucoidan to mice reduces VEGF165-induced angiogenesis and tumor neovascularization in vivo. We find that dextran sulfate and fucoidan can bridge the extracellular domain of NRP1 to that of the scavenger receptor expressed by endothelial cells I (SREC-I), and induce NRP1 and SREC-I coordinate internalization and trafficking to the lysosomes. Overexpression of SREC-I in SREC-I–negative cells specifically reduces cell-surface levels of NRP1, indicating that SREC-I mediates NRP1 internalization. These results demonstrate that engineered receptor internalization is an effective strategy for reducing levels and function of cell-surface receptors, and identify certain sulfated polysaccharides as “internalization inducers.”

Download Full-text