Name the asymmetric junction(s)
Hemidesmosome (attach cells to the basal lamina)
Name the symmetric junction(s)
(btwn two cells) Tight Junction (occluding junction) Anchoring Junction ( belt desmosomes) Anchoring Junction ( spot desmosomes) Communicating Junction (Gap)
Tight Junction (occluding)
No intercellular space -circumferential belts at the apical domain of epthelial cells -links adjacent endothelial cells -regulate the passage of ions between adjacent epithelial cells -
Across the cell controlled by channels and receptors
Between the cells regulated by intracellular contact and CELL JUNCTIONS
Actin filaments are seen in what type of Junction
What is anchored to Zo-1 in Tight Junctions
Afadin-nectin complex JAMS
What type of dimers do Nectins form
JAMS (Junctional adhesion molecules) attach to
afadin and ZO-1
formation of cell polarity
Order of Junctions from the Lumen down
Tight (occluding) Zonula adherens (belt) Macula adherens (spot)
Tight Junctions ..what interacts with F-actin
occludin claudins JAMS
What components of the tight junction are seen in freeze fracture?
Occludin and Claudins
What type of junctions are show from top to bottom
What type of Junction is this?
Tight Junction (freeze fracture) occludin and claudins
What type of Junction is #2
What is inside this intercellular space ?
What type of Tight Junctions are part of the immunoglobin family of Cell Adhesion Moleculess?
Nectin and JAMS
Occludin and Claudin are part of what family of proteins?
What part of Tight Junctions are actin Linkers?
Tight Junctions separate which two domains?
Apical and Basolateral membrane domains
(prevent free diffusion of lipids and membrane proteins between them)
Tight Junctions regulate ...
Paracellular Pathway of fluid and solutes (kidney blood filtration)
Nectin and JAMS form homodimers through what bonds
What type of filaments are associated with tight junctions?
Creates artifical (FACE)
Protoplasmic (wear bumps are seen) where occuludin and claudins seen
Extracellular face (where pits are seen)
results from spitting membrane across hydrophic core
uses heavy metals to coat the cell
Occludin is attached to what ZO
Clauddin is attached to
plaques (desmoplakin, plakoglobin (gamma catenin), plakophillin) *anchor*
catenin ( alpha, beta, gamma) go wit cadherins connect to actin
cadherins ( desmocollins and desmogleins)
What is seen in both tight junctions and belt desmosomes?
Plaques ( belt desmosomes)
where cytoplasmic domains of cadherins attach to desmoplakin by plakglobin and plakophillin
actin filaments (interaction of cadherins with catenins)
wide extracellular space
atttaches to cytoplasmic plaques on cystolicface of plasma membrane
2.desmogleins (1 &3 are in epidermis, if issue the pemphigus foliacus)
issue with Desmogleins 1 & 3 (affects epidermis)
What are the types of juntions seen?
Top is Tight Junction
Bottom is belt desmosome ( can tell because of hte actin filaments but the extracellular space is further apart then the tight )
What are the anchoring desmosomes?
Name a communicating Junction?
Name an occluding Junction?
Keratin/ tonomfilaments/ intermediate filaments
Plaques ( plakoglobin, plakophillin, desmoplakin)
Cadherins (desmocollins and desmogleins)
add strenth and rigidty to epithelium layer
What is anchored to desmoplakin in spot desmosomes?
Differences between belt desmosome and spot desmosome?
spot desmosome has
intermeidate filaments (anchor directly to plaque)
and no catenins
What type of desmosomes are seen in intercalated discs?
Role of Plakophillin
In plaues (spot and belt desmosomes)
recruit protiens to the plasma membranes
Disorder with Desmoglein (cadherin)
striate palmoplantar keratoderma (hypotrichosis)
Issue with desmoplakin (plaque)
Issue with Plakoglobin
ARVC, wooly hair
In this picture of a spot desmosome what is the top line pointing to?
autoimmune disease of the skin
deals with hemidesmosomes
Antibodies to BPAG1 or BPAG2 results in detachment of hemidesmosome fromt he basal lamina
BPAG1 and BPAG2
Integrins (beta 4 alpha 6) +pectin
Intermediate filaments (anchored to the plaque) (inner cytoplasmic plate)
Plaque (DIFFERENT TYPE-NO DESMOPLAKIN, NO PLAKOPHILLIN AND NO PLAKOGLOBIN)
Inner cytoplasmic plate (IF)
outer cytoplasmic plate ( link hemidesmosome to basal lamina with lamisn and integrin)
aids with stability
Link adjacent cells
Connexon: formed by 6 connexins surrounding a central channel
Inner channel: allows direct passage of small signaling molecules (calicum and camp) between adjacent cells (helps with coordinating cell responses)
hyrophiliic inner channel
What junctions tend to have a clustering tendancy?
What junctions are seen in heart muscle cells?
Issue with Connexin 26
Issue with conexin 32
charcot marie tooth demyelinating neuropathay 1
issue with Schawn Cells
Connexin 43 and 45
Role of Basement membrane
supporting sheet epithelia
because of binding affinty to RGD domain in laminin and fibronectin (which are proteins of ECM)
proteoglycans (heparn sulfate)
collagen fibers (III)
supports basal lamina with connective tissue
Things that are PAS POS
glycoproteins (pituitary gland)
3 disuflfide linked polypeptide chains (alpha beta gamma)
binding sites for cells surface receptors (integrins), type IV collagen, nidogen
two identical chains joined by disulfide linkage close to C terminal
Cellular -produced by fibroblas (ECM)
Plasma- produced by hepatocyes (bloodstream)