Cell Interactions - Vocabulary

Flashcards about cell interactions and junctions.

Integrins

Adhesive molecules with both sensing and motility capabilities; found in all animal cells. They bind to adaptor proteins connected to actin filaments and to molecules in the extracellular matrix.

Basement Membrane Layers

Layers of the basement membrane: lamina lucida (electron lucent), lamina densa (electron dense), and lamina reticularis. Cells with integrins attach to the basal lamina.

Hemidesmosomes

Connects the basal surface of epithelial cells to the basal lamina. Inside the cell, it's connected to intermediate filaments; transmembrane proteins are integrins.

Desmosomes

Connect two cells together via linker transmembrane proteins called cadherins. Inside the cell, they connect to intermediate filaments and are common in epithelia to help sustain abrasion.

Adherens

Anchor cells together with a bit of space in between. They are connected to actin filaments and regulate actin polymerization and anchor actin to the cell cortex. Transmembrane proteins are cadherins.

Tight Junctions

So tight that not even ions can pass through (though permeability can be selectively leaky). They are belt-like junctions along the cell, connected to actin, with transmembrane proteins from each cell membrane interlocking across the intercellular space.

Gap Junctions

Form small pores between cells, allowing metabolic & electrical signals (e.g., signals for heart cells to beat), ions, and small water-soluble molecules to pass through. Connexon proteins on both cells’ plasma membranes form a continuous pathway.

Plasmodesma

Like gap junctions in animal cells. Small molecules and ions can pass through. They are made of plasma membrane passing through channels in cell walls.

Connexin Diseases

Different connexin proteins go into different cells in different tissues. Mutations can lead to deafness, nerve defects, skin disease, developmental disorders, and heart beat issues.

Desmosome and Skin Diseases

Autoimmune diseases that target cadherins, destroying cell adhesion between keratinocytes, leading to blister formation.