Related Experiment Video

Updated: Aug 14, 2026

Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
06:45

Transmembrane Domain Oligomerization Propensity determined by ToxR Assay

Published on: May 26, 2011

Analyses of cellular multimerin 1 receptors: in vitro evidence of binding mediated by alphaIIbbeta3 and alphavbeta3

Frédérick Adam1, Shilun Zheng, Nilesh Joshi

  • 1Departments of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.

Thrombosis and Haemostasis
|December 21, 2005
PubMed

Insights

Multimerin 1 (MMRN1) binds to integrins alphaIIbbeta3 and alphavbeta3 on platelets and endothelial cells. This integrin-mediated binding is crucial for MMRN1

Area of Science:

  • Biochemistry
  • Cell Biology
  • Protein Interactions

Background:

  • Multimerin 1 (MMRN1) is a polymeric protein found in platelets, megakaryocytes, endothelium, and extracellular matrix.
  • MMRN1 is known to bind factor V but its cellular receptors were not identified.

Purpose of the Study:

  • To identify the primary receptors for Multimerin 1 (MMRN1) on activated platelets and endothelial cells.
  • To investigate the role of the MMRN1 RGD site in cellular binding and extracellular matrix assembly.

Main Methods:

  • Ligand capture assays
  • Cell adhesion experiments
  • Enzyme-linked immunosorbent assay (ELISA)
  • Flow cytometry
  • Recombinant MMRN1 (wild-type and RGE-mutant) usage

Main Results:

  • MMRN1 binds to integrins alphaIIbbeta3 and alphavbeta3 on platelets.
  • Endothelial cell binding is primarily mediated by alphavbeta3 and does not require the MMRN1 RGD site or cell activation.
  • MMRN1 supports adhesion of other cells, including neutrophils, via alphavbeta3.
  • MMRN1 attachment to cellular receptors enhances its extracellular matrix fiber assembly.

Conclusions:

  • Integrin-mediated binding is key for MMRN1 attachment to platelets and endothelial cells.
  • MMRN1 acts as a ligand for alphaIIbbeta3 and alphavbeta3 integrins.
  • MMRN1's interaction with cellular receptors influences its extracellular matrix assembly.

More Related Videos

Oligomerization Dynamics of Cell Surface Receptors in Living Cells by Total Internal Reflection Fluorescence Microscopy Combined with Number and Brightness Analysis10:43

Oligomerization Dynamics of Cell Surface Receptors in Living Cells by Total Internal Reflection Fluorescence Microscopy Combined with Number and Brightness Analysis

Published on: November 6, 2019

An Analytical Tool that Quantifies Cellular Morphology Changes from Three-dimensional Fluorescence Images10:00

An Analytical Tool that Quantifies Cellular Morphology Changes from Three-dimensional Fluorescence Images

Published on: August 31, 2012

Related Concept Videos

Intracellular Signaling Affects Focal Adhesions01:17

Intracellular Signaling Affects Focal Adhesions

Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Immunoglobulin-like Cell Adhesion Molecules01:31

Immunoglobulin-like Cell Adhesion Molecules

Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs.
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
Integrins01:10

Integrins

Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Enzyme-linked Receptors01:00

Enzyme-linked Receptors

Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Assembly of Signaling Complexes01:30

Assembly of Signaling Complexes

Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...