Cell junctions

what is 2

tight junction

what is 3

adheren junction

what is 1

desmosomes

Hemidesmosomes function is

cell-substratum adhesion

What is also attached to keratin

hemidesmosomes

Focal adhesions function is

cell motility, survival signals

Focal adhesions is attached to

actin

Gap junctions have what function

passage of solutes, communication

How are gap junctions attached to the cytoskeleton

no connection

What junctions are known for cell-cell adhesive strength (abbreviated)

AJ, D

Where are gap junctions, adheren junctions, desmosomes, tight junctions located

lateral membrane

Where are hemidesmosomes and focal adhesions located

basal membrane

Which cellular junction plays a key roles in cell locomotion

focal adhesion

Focal adhesions are

dynamic

focal adhesion are [blank] and [blank]

made, break easily

what binds hemidesmosomes

keratin intermediate filaments to integrin proteins

what binds focal adhesion

actin cytoskeleton to integrins to ecm

what sends a signal of survival to the nucleus

integrin signalling layer

what happens if there is no signal of survival to the nucleus

apoptosis

talin links

integrin to actin

what is needed for cell survival and proliferation

focal adhesion kinase (FAK), SRC kinase

Hemidesmosomes contain

dense cytoplasmic plaque, keratin filaments

What are the keratin filaments linked to in hemidesmosomes

ECM

How are keratin filaments linked to

integrins to ECM

What are hemidesmosomes anchored to

basement membrane

What type of channel is gap junction

communication

Gap junctions form

intercellular channels

What is made up of connexin proteins

gap junctions

connexin proteins are

1 subunit

what is a connexon

6 connexin proteins together

to form a transmembrane channel with a central pore is called

connexon

how many connexons form a gap junction

two

how many connexin proteins are in a gap junction

12

what is the size restriction in gap junctions

< 1000 Da

the central pore is

hydrophilic

what else provides tissue strength other than adheren junction and desmosomes

hemidesmosomes

Gap junctions are what type of communication

1 way

Even though gap junctions are 1 way communication it is [blank] cytoplasm

between two

Hemidesmosomes are

stationary

Keratin intermediate filaments in epithelial cells go

around nucleus

Cytoplasmic plaque has 3 characteristics

strength, made of keratin, electron dense

Desmosomes use what type of binding to anchor two cell together

intermediate filament

When cadherins interact with multiple proteins, what does it form

cytoplasmic plaque

Where does this cytoplasmic plaque form

inner surface of the plasma membrane

Cadherins interact with

multiple proteins

Desomosomes also contain

cadherins

Desmosomes primarily

adhesive

adherens junctions, desmosomes increase

tissue strength

what do adherens junctions connect

external enviroment to actin cytoskeleton

adheren junctions attach to

actin cytoskeleton

desmosomes attach to

keratin

adheren junctions provide a [blank] for signals to be transmitted

pathway

where are signals transmitted from (adheren junctions)

exterior to the cytoplasm and nucleus

zonula adherens are

AJ that form a belt that encircles the cell

AJ forms a belt near their

apical surface in epithelial cells

What are the two type of tight junctions

gate, fence

How does TJ contribute to cell polarity?

forming a barrier that blocks proteins

The function of tight junctions in general

cell-cell permeability and cell polarity

Tight junctions bind to

actin cytoskeleton

Fence function

blocks diffusion between apical – basolateral

Whats the cell attachment of tight junctions

neighbouring epithelial

Gate function

controls ion, protein, water between cells

What is the gate function also called what pathway

paracellular

Tight junctions are also known as

zonula occluden

Desmosomes are also known as

macula asheren

What can you use to visualize cell junctions

electron microscopy

Electron microscopy uses

electrons

What type of cells cannot be imaged in electron microscopy, why

live, vacuumed

Electron microscopy is also called

TEM (transmission)

what type of integrin does the top one represent

inactive

what does the bottom one represent

active

how do we know the bottom one is active?

there is space for activation

what is this a picture of?

breast cancer cells

what is this a picture of?

normal cell

What happens when trypsin is added [] get cut

cadherins, integrins

What would disrupt cell adhesion [_,_]

Small peptides containing RGD, trypsin

Integrins often interact with

ECM proteins

What extend further than glycocalyx

ECM

Glycocalyx extends only a [] from the cell membrane

small distance

Fibronectin description is

interactive dimer

The function of fibronectin is to

linked to multiple molecules, improve signal survival

What are MMPs

matrix metalloproteases

What MMPs for connective tissue collagen

collagenases

What MMPs basement membrane collagen, gelatin

gelatinases

What MMPs for proteoglycan, laminin, fibronectin, gelatine

stromelysins

What does a neutrophil need to migrate through collagen

MMP

MMP are..

enzymes that can chop

Without MMP what happens to neutrophils in collagen

cant get through

Laminin are made up of [], linked by []

3 different proteins, disulfide bonds

What is involved in migration, growth differentiation

laminin

Differentiation is also known as

specialization

What forms separate but interconnected networks

laminin, collagen IV

what look like trimers organized into a cross-like shape

laminins

Proteoglycan look

feather like

Proteoglycan form a [blank] how [proteoglycans bind to_ which bind to_]

porous hydrated gel, cations, water molecules

Porous hydrated gel results in

increased resistance to crushing or compression

Increased resistance to crushing or compression is great in

joint

What provides ECM strength and resistance [_,_]

collagen, proteoglycan

What do proteoglycans consist of

core protein

The core protein in proteoglycans [], attached []

covalently, glycosaminoglycans