Tissue Architecture Flashcards
What are the three types of cytoskeletal filaments are there?
Intermediate filaments
Microtubules
Microfilaments
Filament with great tensile strength due to rope-like properties
Intermediate Filaments
Filament significant in chromosomal segregation
Microtubules
filament that forms the nuclear lamina
Intermediate filaments
Actin filament (F-action) Twisted polymer of G-actin
Microfilaments
Filament that creates “tracks” to transport vesicles organelles & other cell components
Microtubules
Unstable filaments that are stable when associated with other proteins
microfilaments
Filament essential for cell movements
Microfilaments
Form a mesh network throughout cytoplasm
Often anchored to plasma membrane at cell-cell junctions
Intermediate filaments
Mutation in nuclear lamina causes
Cellular aging
Rapid assembly & disassembly
Form mitotic spindle
Part of cilia & flagella
Microtubules
Made of an alpha & beta heterodimer
Microtubules
Purpose of gamma-tubulin
Forms nucleus/centrosome that attach to the negative end
Positive end protrudes out and microtubules grow there
4 characteristics of cytoskeletal filaments
Strong, stability, dynamic & adaptable
Drug that binds & stabilizes microtubules
Does not all for microtubule growth & prevent functionality
Taxol
Drug that binds tubulin dimerrs & prevents their polymerization
Colchicine, colcemid
Vinblastine, vincristine
Caused by a mutation in collagen or collagen synthesis enzymes
Ehlers-Danlos Syndrome
Disease that results in loss of co-factor in hydroxylation of collagen monomers to make polymers
Scurvy
Functions of extracellular matrix
Interacts with cells via transmembrane proteins
Anchor/cluster cells into tissues with distinct functions
Determine biochemical properties
Control cell polarity, survival, proliferation
Facilitate cell migration
Function of proteoglycans in the ECM
Provides hydration and swelling pressure to the tissue enabling it to withstand compression forces
Function of collagen in extracellular matrix
Direct flow of growth factors, facilitate cell migration & regulate inflammation
Function of multiadhesive matrix proteins in ECM
Attach cells to ECM
Binding a variety of protein and signaling molecules like growth factors & hormones
Collagen associates in ECM as
Fibers, sheets, or transmembrane structures
Junctions
Cell-cell or cell-matrix adhesion
Important in keeps cells together & structural cohesion
Anchoring junctions
also known as tight junctions
Prevent leakage of transported solutes and water
Occulding junction
Focal contacts link cells to
ECM or basil lamina
Form channels to allow things to come in and out
Channel-forming junctions
Sending signal from cell to cell or cell to matrix
Signal-relaying junctions
CAMs: 3 major domains
Extracellular
Transmembrane
Cytoplasmic
CAM domain that binds to adjacent cell/matrix proteins
Extracellular
CAM domain that links CAM to membrane
Transmembrane
CAM domain that binds to cytoskeleton via linker proteins
Cytoplasmic
4 major families of CAM
Cadherins
Ig-superfamily CAMs
Integrins
Selectins
Name the classic type I cadherins
E-cadherin & N-cadherin
Type II classic cadherins
VE-cadherin
Atypical cadherins
LI-cadherin (liver-intestine)
Cadherins with well-established Ca2+ dependent homophilic adhesion function
Linked to actin cytoskeleton
Classic cadherins
Cadherins that function as homophilic adhesion proteins without link to actin cytoskeleton
Atypical cadherins
CAMs that are calcium—independennt
Immune cell interactions
Homophilic & heterophilic binding
Involved in recognition, binding or adhesion of cells
Ig Superfamily CAMs
Family of Ca2+ dependent glycoproteins
Bind to extracellular carbohydrates
Low affinity interaction -> allows for “rolling”
Selectins
L-selectin
Leukocyte
P selectin
Platelet
E-selectin
Endothelial
CAM that couple the ECM to cell cytoskeleton
Cell-cell interactions via B2 family -> allow diapedesis
Can activate signal pathways
Integrins
