Q13 - GSK3 and Beta-Adrenergic Control of Thermogenic Genes

Theoretical 2 Real exam question - full text reproduced under IBO's CC BY-NC-SA 4.0 license

Brown adipose tissue (BAT) activation through beta-adrenergic signalling pathway is associated with expression of thermogenic genes and the process of thermogenesis. Glycogen synthase kinase-3 (GSK3) acts as a regulator of beta-adrenergic signalling in brown adipocytes. ISO is also a chemical stimulator of BAT activation; its effect on GSK3 is shown by the Western blot below (p-GSK3 is phosphorylated form of GSK3). SB216763 is an inhibitor of GSK3. Effects of these two agents on the expression of thermogenic genes (Fgf21, Ucp1, Dio2, and Ppargc1a) are shown in the Figure below. (*) shows significant difference as compared to control (H2O)

Figure 1. Figure 1.

Using the information and data, determine which of the statements are true or which are false.

A. GSK3 acts as a negative regulator of beta-adrenergic signalling in brown adipocytes.

B. Phosphorylation of GSK3 causes decreased expression of Fgf21.

C. SB216763 may prevent diet-induced obesity.

D. Use of SB216763 and ISO together cause much higher increase in the number of Ppargc1a mRNA transcripts as compared to Fgf21 mRNA transcripts.

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Question reproduced from IBO 2018, Theoretical Paper 2, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)