3 You are examining the behavior of two centrosomal proteins

3.

You are examining the behavior of two centrosomal proteins Centrin and Cep192 by FRAP analysis. Both proteins are expressed as GFP-tagged forms, which localize to the centrosome (centrosome is indicated by red arrow). p.b. is before bleaching, the subsequent images show time points during recovery from photobleaching (time is indicated in minutes and the time course shows the fluorescent signal at the centrosome over time, always focusing on the centrosome).

Which of the following conclusions can you draw from this experiment?

The legend to this figure (taken from a research paper by Zhu et al., 2008. Current Biology 18, 136-141)

FRAP analysis of HeLa cells expressing GFP-tagged murine Centrin-2 or murine Cep192. Images were taken before (p.b.) and immediately after photobleaching (0) and every 2 min afterwards. Insets show 6-fold magnifications of the centrosomal region. The scale bar represents 10 m.

A. Both, Centrin and Cep192 are stably associated with the centrosome and do not exchange with cytosolic subunits,

B. Centrin-GFP displays a more dynamic behavior than Cep192

C. Cep192-GFP is more dynamic than Centrin

D. This experiment reveals that centrosome duplication depends on Cep192

E. This experiment reveals that centrosome duplication depends on Centrin

Solution

Ans) By the above experiment and images can conculed that its displays the centrinGFP

B. Centrin-GFP displays a more dynamic behavior than Cep192