click below
click below
Normal Size Small Size show me how
Burridge -Exam2
Cells
Question | Answer |
---|---|
connective tissue | lots of ECM few cells |
epithelial tissue | tightly bound sheets of cells, sparse ECM (basement membrane) |
tight junctions | "O-ring" seal, separate apical and basolateral surfaces, prevent movement between |
glycocalyx | CHO-rich coating on cells |
junctional complex | tight junctions, adherans junctions, and desmosomes |
zona adherans | continuous jxn around cell, strong adhesion btwn cells and attachment to microfilaments |
desmosomes (macula adherans) | spot welds, keratins/tonofilaments attach to them |
hemidesmosomes | spot weld to basement membrane, serves as attachment for integrin IFs |
focal adhesion | seen in TC and scar contracture, strong adhesion to ECM and attachment for microfilaments |
Gap junctions (communicating junction) | allow passage of molecules (<1500kDa) through connexons, permeability regulated by Ca and pH |
actin decoration | bind myosin head to actin for identification with EM |
phalloidin | dervied from fungus, prevents depolymerization of microfilaments |
G-Actin | unpolymerized actin |
Gels or Networks of Actin | actin filaments crosslinked with binding proteins-->rigidity |
dyneine motor | move stuff to minus end of MT (act at kinetochores during anaphase) |
kinesin motor | moves stuff to + end of MT (pushes poles apart during anaphase) |
Cadherins | Ca dependant CAM - homophilic glycoproteins, link to actin and some found in desmosomes |
Ig CAM | Ca independant - hetero or homophilic binding, includes ICAM and NCAM, found on surfaces of neural, lymphoid, and endothelial |
selectins | Ca dependant protein CAM, binds to CHO, found on leukocytes and endothelial cells, include PMNs |
Fibronectin | ECM component-large disulfide linked dimeric protein, multi domains, RGD domain critical binding seq, important for cell adhesion and migration (found in focal adhesions) |
laminin | ECM component -in BM, binding site for other ECM components |
elastin | ECM component- BV,lungs,and skin-associates w/ fibrillin (def. in Marfan) |
GAGs and proteoglycans | ECM component- makes cavities(embryo) and resists forces (joints) |
integrins | receptor for many ECM components, alpha and beta subunits span membrane often concentrated at myotendinous jxns and focal adhesions interact w/ actin, talin, filamin, and alpha actinin |
integrin a5B1 | Fn receptor binds only Fn RGD |
integrin avB3 | Vitronectin receptor binds several RGD |
integrin aLB2 | on leukocyte binds ICAM-1 on other leukocytes and endothelial cells --> inflammatory response (def. in LAD) B2 family is target of antiinflammatory drugs |
integrin aIIbB3 | on platelets, bind fibrin/fibrinogen via RGD --> clotting (def in Glanzmann's) target of anticlotting drugs |
B4 integrin | long cytoplasmic domain, found in hemidesmosomes, binds tonofilaments/keritins |
microfilaments | actin, myosin |
cytochalasin | inhibits actin polymerization |
gelsolin | dissassembles actin gels |
actin bundles | contractile ring, microvilli, stereocilia, focal adhesions |
focal adhesions | AKA stress fibers- actin bundles associate w/ integrins via vinculin, talin, and alpha actinin |
GTP Rho | stimulates stress fibers and focal adhesions |
GTP Rac | stimulates ruffles and lamellipodia |
GTP Cdc42 | stimulates filopodia |
MLCK | ca regulated protein kinase in smooth muscle -->induces active conformation of myosin |
Rho-kinase | activated by Rho-->phosphorylates light chain of myosin II AND inhibits phosphatase that reverses action |
troponin | regulated by Ca in striated muslces |
spectrin | binds F actin to ankyrin (in PM)--> biconcavity of RBC |
Cell extension | regulated by Rac and Cdc42 |
Cell adhesion | regulated by CAMs |
Cell contraction | regulated by Rho |
Taxol | prevents depoly of MT |
Colcemid, Colchecine, nocodozole, vinblastin | causes depolymerization of MT |
Type 1 IF | tonofilaments, keratins, cytokeratins |
tonofilaments | insert into desmosomes and hemidesmosomes |
keratins | tissue specific, defective in EBS |
Type 2 IF | crosslink to other MT, e.g. vimentin to MT in fibroblast |
Type 3 IF | neurofilaments, primarilty structural, crosslink MT and actin |
Type 4 IF | nuclear lamins, provide structure to nucleas, phosphorylation disintegrates them for mitosis |
Nulclear Pore movements | in/out determined by NLS and regulated by Ran |