Intercellular Structure and Extracellular Matrix

This set of flashcards covers essential vocabulary related to intercellular structures and the extracellular matrix, including definitions and functions.

Cell-cell adhesion molecules (CAMs)

Proteins that mediate the adhesion between cells and to the extracellular matrix.

Cadherins

Calcium-dependent adhesion molecules that bind homophilically to the same types of molecules.

• calcium sensitive

• bind when calcium is present and release when calcium is low

Selectins

Heterophilic CAMs that bind to carbohydrates, facilitating cell adhesion.

• ion sensitve

Integrins

Heterophilic CAMs that bind to the extracellular matrix and connective tissues.

• bind type III intermediate filaments

• ion sensitive

Immunoglobulin superfamily (Ig) CAMs

Diverse CAMs that can participate in both homophilic and heterophilic binding interactions.

• ion insensitive

Mechanotransduction

The process by which cells convert mechanical stimuli into biochemical signals.

Tight junctions

Cell junctions that prevent the diffusion of materials between cells, maintaining polarity.

• most common at endo/exothelial tissues; also found at blood-brain barrier, digestive system,blood vessels

• membrane diffusion still occurs, but diffusion between cells does NOT happen

• formed by weaves of integral proteins occludin,claudin, and junctional adhesion molecules (JAMs)

• maintain polarity and create a barrier

• hold cell together

Gap junctions

Channels that allow for the direct transfer of ions and small molecules between neighboring cells.

• permit diffusion of cytosol for adjoining cells

• formed by rings of connexins, innexins, pannexins-exit motifs

• can open/close but aren’t traditional channel proteins ( limited by pore size)

• permit rapid communication between cells

Anchoring junctions

Junctions that help hold cells together or attach them to the extracellular matrix.

• focal contact are made of cadherin looped to microfilaments

• desmosomes are made of cadherin looped to intermediate filaments

• hemidesmosomes are made of integrin looped to intermediate filaments

• used for strength, shape, signaling

Basal lamina

The layer of the extracellular matrix closest to the cells, providing a foundation for tissue growth.

Interstitial matrix

A loose network of proteins and carbohydrates that provide a jelly-like consistency and structural support.

Metastasis

The process by which cancer cells spread from the primary tumor to other parts of the body.

N-cadherin

A type of cadherin that promotes cell migration and is associated with metastasized cancers.

Fibroblasts

Cells that provide structural support and are involved in tissue repair and ECM remodeling.

Collagen IV (Col IV)

A major protein in the basal lamina that provides structural support and stability.

Proteoglycans

Polysaccharides that attract and hold water, contributing to the jelly-like consistency of the interstitial matrix.