Following statements are regarding to the FOXO3a protein.

A. In the presence of growth factors, FOXO3a is non phosphorylated and mainly localizes to the nucleus, where it activates transcription of several genes encoding pro-apoptotic proteins.

B. When growth factors are removed from the cells, PKB becomes active and phosphorylates FOXO3a.

C. Phosphorylated FOXO3a binds to cytosolic phosphoserine-binding protein 14-3-3 to bind FOXO3a and thus sequester it in the cytosol.

D. Dephosphorylated FOXO3a binds to cytosolic phosphoserine-binding protein 14-3-3 to bind FOXO3a and thus sequester it in the cytosol.

Which of the following is correct?

TLS Online TPP Program

#Question id: 1106

#Unit 4. Cell Communication and Cell Signaling

Protein kinase is an enzyme that functions in which of the following ways?

TLS Online TPP Program

#Question id: 1108

#Unit 4. Cell Communication and Cell Signaling

Which of the following amino acids are most frequently phosphorylated by protein kinases in the cytoplasm during signal transduction?

TLS Online TPP Program

#Question id: 1107

#Unit 4. Cell Communication and Cell Signaling

Viagra causes dilation of blood vessels and increased blood flow to the penis, facilitating erection. Viagra acts by inhibiting which of the following events?

TLS Online TPP Program

#Question id: 1109

#Unit 4. Cell Communication and Cell Signaling

What role do phosphatases play in signal transduction pathways?

TLS Online TPP Program

#Question id: 1110

#Unit 4. Cell Communication and Cell Signaling

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound that does which of the following?

TLS Online TPP Program

#Question id: 14740

#Unit 4. Cell Communication and Cell Signaling

Rod cells sense light with the aid of a light-sensitive GPCR known as rhodopsin; choose incorrect statements

a. Rhodopsin consists of the protein opsin, which has the usual seven–transmembrane segment GPCR structure, covalently linked to a light-absorbing pigment called retinal. 

b. Rhodopsin, found only in rod cells, is localized to the thousand or so flattened membrane disks that make up the inner segment of each of these rod-shaped cells.

c. A human rod cell contains about 4 × 10⁷ molecules of rhodopsin. 

d. The heterotrimeric G protein coupled to rhodopsin, called transducin (Gt), contains a Gα unit referred to as Gαt; like rhodopsin, Gαt is found only in rod cells.