Disorders of TGF Signaling

Question 1

Mutations in the gene coding for fibrilin-1 would cause which disease?

Answer 1

Marfan syndrome

Question 2

homolog vs orthalog vs paralog

Answer 2

homolog: genes with similar but not totally identical copies in the genome. Homologs can be paralogs or orthologs. Paralogs are from the same species. Orthologs are from different species.

Think implications for evolution

Question 3

One of the roles of proteins encoded by fibrilin genes is:
A. to aid glucose metabolism
B. to aid in ion transport
C. to provide a hard outer exoskeleton
D. to provide stength and flexibility in blood vessels
E. to transport oxygen

Answer 3

D. to provide stength and flexibility in blood vessels

remember, fibrilin 1 = Marfan syndrome

Question 4

Disruption of transglutaminase (T-glutaminase) disulfide bonds between fibrilin molecules leads to
A. increased fibrilin-1 aggregation
B. increased microfibril formation
C. irreversible extension of microfibril structure
D. trapping of TGF-beta proteins
E. tropoelastin deposition

Answer 4

C. irreversible extension of microfibril structure

remember, fibrilin 1 = Marfan syndrome

Question 5

What is the heart condition related to Marfan syndrome?

Answer 5

Dilation of ascending aorta involving the sinuses of valsalva

Question 6

Fibrilin-1 cross-links with other fibrilin-1 molecules to form microfibrils in the…
A. cytoplasm
B. extracellular matrix
C. Golgi apparatus
D. mitochondria
E. nucleus

Answer 6

B. extracellular matrix

Question 7

Recent sudies on Marfan syndrome revealed that in addition to serving as a structural protein in the extracellular matrix, fibrilin-1 alsol
A. helps with cross linking of collagen
B. modulates TGF-Beta signaling
C. represents a major source of energy during starvation
D. serves as a Beta-adrenergic agonist
E. serves as a lens protein

Answer 7

B. modulates TGF-Beta signaling