Cmbm- Exam 3- Molecular Mechanisms Of Cell Adhesion

Front 1

What time of cellular junction seals the gap between cells in epithelia?

Back 1

Occluding junctions

Front 2

What is the most important class of proteins that mediate cell to cell attachment?

Back 2

Cadherins

*Mediate cell to cell attachment at adherens junctions (actin filaments) and desmones (intermediate filaments)

Front 3

Where are N-cadherins expressed?

Back 3

Nerve, muscle, lens

*type of classical cadherin

Front 4

Where are E-cadherins expressed?

Back 4

Epithelial cells

*type of classical cadherin
*Germ line mutation can predispose to familial gastric carcinoma

Front 5

At what type of junction are cadherins most commonly found?

Back 5

Anchoring Junctions

*Adherens (actin) or Desmosomes (IF)

Front 6

What protein assembles on the tail of the cadherin molecule and binds actin?

Back 6

B-catenin

*Adherens junction = cadherin + catenin

Front 7

What is the main function of adenomatour polyposis coli (APC)?

Back 7

Down-regulate growth promoting signals (tumor suppressor)

*mutants born with one mutant allele develop thousands of colon polyps

Front 8

What happens to B-catenin when WNT binds its receptor?

Back 8

B-catenin is released from the destruction complex (APC) and it moves into the nucleus, where it up-regulates cell proliferation

Front 9

Name the 3 types of selectins

Back 9

1) L-selectin (lymphycytes/leukocytes)
2) P-selectin (platelets, endothelial cells in an inflammatory response)
3) E-selectin (endothelial cells)

Front 10

What is the role of selectins?

Back 10

Mediate transient cell to cell adhesions in the bloodstream

Front 11

What type of selectin is a homing receptor for lymphocytes to enter lymph nodes by binding to high endothelial venules?

Back 11

L-selectin

*also serves to bind neutrophils to endothelial cells during inflammation

Front 12

What is the hallmark of acute cytokine mediated inflammation?

Back 12

Endothelial expression of E-selectins

Front 13

What type of selectin is transferred to the surface of platelets or endothelial cells and bind neutrophils, T lymphocytes and monocytes?

Back 13

P-selectin

Front 14

What is the name for secretory granules of endothelial cells?

Back 14

Weibel-Palade bodies

Front 15

What is the name of the integrin-binding protein that involved in adhesion of cells to the matrix?

Back 15

Fibronectin

*In ECM

Front 16

Which important B2 integrin plays an important role in the adhesion of lymphocytes and other leukocytes with other cells (APCs)

Back 16

LFA-1 (CD11aCD18)

*Binds members of Ig superfamily (ex: ICAM-1 on endothelial cells)