Flashcards in Cell Structure Deck (123)
What special structure is present in the stratum granulosum that binds keratin filaments together?
Keratohyaline granules (they are filled with histidine and cysteine rich proteins which bind the keratin filaments together)
What level of the epidermis are keratohyaline granules found?
What substances do keratohyaline granules (present in stratum granulosum) contain?
Profilaggrin, loricrin, and involucrin
Where is fillagrin located?
What does filaggrin do?
Binds Keratin (like K 6/16) intermediate filaments and organizes into fibrils (like the glue that binds the keratins)
Where is filaggrin located?
In the keratohyaline granule in the stratum granulosum
Keratins found in the stratum granulosum
K2 and K10 (K11)
What enzyme crosslinks peptide bonds in the cornified envelope to make it into the insoluble compound y-glutamic lysine isopeptide bonds
What is the major protein component of the cornified envelope?
What enzyme crosslinks all the protein peptide bonds loricrin and involucrin to make the cornified envelope?
What are the two major proteins that make up the cornified envelope?
Involucrin and loricrin (fillagrin is the glue)
Which cornified envelope protein is the substrate for transglutaminase
Involucrin (this is the one that is upregulated in psoriasis)
What two cell proteins are upregulated in psoriasis, and which is downregulated?
Involucrin and K6/16 is upregulated
Loricrin is downregulated
(P5 in Jain)
Substrate for transglutaminase in the cornified envelope
Upregulated in all layers in Psoriasis except basal
Components of the basal layer (as a part of the DEJ)
Basal layer keratinocytes, part of the BMZ complex/DEJ
Hemidesmosome anchoring filament proteins
BPAG 2 (Collagen XVII)
Alpha-6, beta-4 integrin
Laminin 332 (Laminin 5)
Same thing as BPAG II
What collagen is found in the lamida Lucida/basal layer
Collagen XVII - same thing as BPAG II
A Heim-desmosome anchoring filament protein - found in the basal layer/lamida lucida along with BPAG I,II, integrin, and laminin 5 (332)
What type of collagen is found in the lamida densa?
Type IV collagen found where?
Major components of lamina densa?
Type IV Collagen
Heparin Sulfate proteoglycans
Laminin 311 (6) Laminin 511 (10)
(Also tecnically some of laminin 5(332)
Major components of the sublamina densa
Type VII collagen
Type III collagen
Type I collagen
Latent TGB-beta proteins
Where is type VII collagen found?
Major protein comprising Anchoring Fibrils?
Type VII Collagen
What are anchoring fibrils made of and where are they found?
Made of Type VII collagen and they are found in the sublamina densa
What protein connects the lamida lucida to the lamina densa?
Laminin 332 (Laminin 5)