Exam 4: Zima Lecture

Question 1

Adherin junctions are specialized cell junctions that form by linking the ____ to transmembrane proteins known as ______

Answer 1

Adherin junctions: link actin cytoskeleton to cadherins

Question 2

______ is involved with anchoring the extracellular matrix to the cell?

Answer 2

Hemidesmosomes are involved with anchoring the extracellular matrix to the cell.

Question 3

What are the two major proteins that comprise tight junctions?

Answer 3

Tight junctions: claudins and occludins

Question 4

What is Epithelial-Mesenchymal Transition (EMT)?

Answer 4

EMT is the process by which epithelial cells lose their cell to cell adhesion by switching from E to N cadherin

Question 5

What is anoikis?

Answer 5

Anoikis is the process of cell death due to detachment from EMT

Question 6

What is the role of FAK in cell survival?

Answer 6

FAK plays a key role in cell survival signaling When FAK is activated, it prevents apoptosis. Inactivation of FAK after cell detachment causes cell death.

FAK is overexpressed in cancer cells.

Question 7

What is gap junction channel formed by?

Answer 7

Gap junctions are a channel formed by two connexons

Question 8

Proteins of the cadherin superfamily:

Answer 8

Proteins of the cadherin superfamily mediate cell to cell attachment

Question 9

Gap junctions are intercellular junctions that are involved in _______

Answer 9

Gap junctions are intercellular junctions that are involved in rapid chemical coupling between adjacent cells

Question 10

Proteins of the integrin superfamily…..

Answer 10

Proteins of the integrin superfamily primarily mediate cell attachment to the extracellular matrix

Question 11

If two types of cells are mixed in a CALCIUM FREE enviornment (with one cell expressing N-cadherin and the other E-cadherin), what do you expect to happen?

Answer 11

Cells cannot form aggregates and will die from apoptosis

(because there is no calcium)