concept

Extracellular matrix (ECM)

The extracellular matrix (ECM) is found in the spaces between cells, forming a large proportion of tissue volume. It is also found between organs and as such contributes to the body's shape, plasticity, and partitioning. The ECM is composed of three associated macromolecules: (1) fibrous structural proteins such as collagen and elastin, (2) glycoproteins, and (3) proteoglycans and hyaluronic acid. Typically, the ECM forms either basement membrane or interstitial matrix and, in doing so, performs several functions, including retaining water, minerals, and nutrients as well as acting as the substrate for cell-cell contact, migration, and adherence. The extracellular matrix occupies the intercellular spaces. It is most abundant in connective tissues such as the basement membrane, bone, tendon, and cartilage, where definition is given to the ECM by the proportions and organization of various components. The elastin of skin and blood cells provides resiliency, collagen provides strength to tendons, and the calcified collagen matrix of bone provides strength and incompressibility. Integrins are a family of heterodimeric proteins composed of α and β subunits that are the main cellular receptors for the ECM. Integrins have several distinctive features from other adhesion proteins. They interact with an arginine-glycine–aspartic acid (RGD) motif of ECM proteins. Integrins link the intracellular cytoskeleton with the ECM through this RGD motif. Without this attachment, cells normally undergo apoptosis. Integrins can bind to more than one ligand and many ligands can bind to more than one integrin. Examples of integrins include fibronectin receptors and laminin receptors.

Ref:
Linda R. Adkison PhD, in Elsevier's Integrated Review Genetics (Second Edition), 2012

20 confidence points
0 comments
Added on Apr 20, 2023 by Barbara Van De Keer
Edited on May 11, 2023 by Barbara Van De Keer

Join Ninatoka!!

NinatoKa's goal is to support you as a therapist in unravelling the illness pathway from symptoms to cause, and to help you detect potential interventions.

Go to Explore to start your discovery!

Go to Learn to scroll through newly added data.

Go to Contribute to contribute to the Ninatoka database.

You can rate content up or down and add comments if you agree or disagree.