Question

Hgs is a major target of the Ire1-dependent RNA decay pathway. Mutation of a particular stem-loop sequence in the Hgs mRNA abolishes its degradation during ER stress. What would you conclude from this result?

1. the stem-loop is necessary and sufficient for degradation
2. the stem-loop is sufficient for degradation
3. the stem-loop is necessary but not sufficient for degradation
4. the stem-loop is necessary for degradation

Which of the following processes is most likely to be affected by lysosome localization/positioning in the cell?

1. protein secretion
2. autocrine signaling
3. autophagy.
4. disulfide bond formation.

Which of the following statements is true?

1. Paracrine signaling involves the secretion of signals into the bloodstream for distribution throughout the organism.
2. Because endocrine signals are broadcast throughout the body, all cells will respond to the hormonal signal.
3. The axons of neurons typically signal target cells using membrane-bound signaling molecules that act on receptors in the target cells.
4. The regulation of inflammatory responses at the site of an infection is an example of paracrine signaling.

Which of the following mechanisms is not directly involved in inactivating an activated RTK?

1. removal of the RTK from the plasma membrane by endocytosis
2. dephosphorylation by serine/threonine phosphatases
3. dephosphorylation by protein tyrosine phosphatases
4. digestion of the RTK in lysosomes

Indicate by selecting “yes” or “no” whether signal amplification can occur at the GPCR signaling steps described below.

1. An extracellular signaling molecule binds and activates a GPCR.   
2. The activated GPCRs cause Gα to separate from Gβ and Gγ.
3. Adenylyl cyclase produces cyclic AMP.   
4. cAMP activates protein kinase A.
5. Protein kinase A phosphorylates target proteins.

Answer 1