In mice engineered to overexpress the syndecan-1 gene in the hypothalamic region of the brain and other tissues, normal control of feeding by antisatiety peptides is disrupted, and the animals overeat and become obese. Other studies have shown that syndecan-3 may also be involved in the regulation of feeding behavior. Given the following information, which of these outcomes might you expect in experimentally manipulated mice?

I. Hypothalmic expression of syndecan-3 is increased by fasting.

II. Syndecan-3 knockout mice are resistant to diet-induced obesity.

III. Heparinase can cleave syndecan-3 to release heparin sulfate GAG chains that may suppress the activity of antisatiety peptides and feeding behavior.

Following statements are:

A. Overexpression of heparinase in mice with normal levels of syndecan-3 would result in resistance to diet-induced obesity.

B.  In mice with normal levels of syndecan-3, fasting followed by free access to a high-fat diet would lead to resistance to diet-induced obesity.

C. Lack of heparinase in mice with normal levels of syndecan-3 would result in animals that overeat and become obese.

D. Overexpression of heparinase in syndecan-3 knockout mice would reverse the resistance to diet-induced obesity.

Which of the following combination is correct?

#Question id: 10968

#Unit 7. System Physiology – Animal

Which of the following is TRUE concerning erythroblastosis fetalis (hemolytic disease of the newborn, HDN)?

#Question id: 3886

#Unit 3. Fundamental Processes

Which one of the following statements about the reverse transcriptases of retroviruses and the RNA replicases of other single-stranded RNA viruses, such as R17 and influenza virus, is correct?

#Question id: 4300

#Unit 3. Fundamental Processes

Find correct order of cotranslational translocation in endoplasmic reticulum

A. Transfer of the nascent polypeptide–ribosome to the translocon leads to opening of this

translocation channel to admit the growing polypeptide adjacent to the signal sequence, which is transferred to a hydrophobic binding site next to the central pore. Both the SRP and SRP receptor, once dissociated from the translocon, hydrolyze their bound GTP and then are ready to initiate the insertion of another polypeptide chain.

B. As the polypeptide chain elongates, it passes through the translocon channel into the ER lumen, where the signal sequence is cleaved by signal peptidase and is rapidly degraded.

C. The SRP and the nascent polypeptide chain–ribosome complex bind to the SRP receptor in

the ER membrane. This interaction is strengthened by the binding of GTP to both the SRP and its receptor.

D. The ER signal sequence emerges from the ribosome; it is bound by a signal recognition particle (SRP).

#Question id: 31354

#Unit 1. Molecules and their Interaction Relevant to Biology

#Question id: 1938

#Unit 4. Cell Communication and Cell Signaling

Which of the following antibodies are useful for the diagnosis of Sjögren's syndrome?