Cell Junctions

Location of Tight junction within body

stomach, intestines and bladder

Function of Tight Junctions

Keep cell polarity by preventing migration of proteins between apical and basal surfaces. Joins cytoskeletons of adjacent cells.

key proteins in tight junctions

Claudins and Occludins

Function of Adherens Junctions

Prevent cell separation from tension forces like in contractions

Term for less continuous belts in adherens junctions

adhesion plaques

What is Plaque in Adherens junctions

a layer of proteins on the inside of the cell to join actin to cadherins

Transmembrane glycoprotein in adherens junctions

Cadherins

function of catenins

link the cadherins to actin

Function of Desmosomes

Resist shearing forces

Intermediate filament in Desmosomes

Keratin

Function of cadherin in Desmosmes

Span intercellular space and bind to desmoplakin which binds to Keratin

Function of Keratin (desmosomes)

Span from one desmosome to another on other side of the cell. Structural integrity.

Function of Gap junctions

Direct connection between cells

Gap junction is made of

2 hemichannels

Amount that can pass through gap junctions

1kDa, small molecules

Function of Hemidesmosomes

Connect epithelia to BM and link cellular basal intermediate filament to BM

Transmembrane glycoprotein in Hemidesmosomes

INTEGRIN

Function of INTEGRIN

Linker protein that binds to LAMININ in the BM and to keratin

Junctional complex

Tight junction, adherens junction, desmosomes junction