Exposure of zebrafish nuclei to cytosol isolated from eggs at metaphase of mitosis resulted in phosphorylation of NEP55 and L68 proteins by cyclin-dependent kinase 2. NEP55 is a protein of the inner nuclear membrane, and L68 is a protein of the nuclear lamina. What is the most likely role of phosphorylation of these proteins in the process of mitosis?
A) They enable the attachment of spindle microtubules to kinetochores.
B) They are involved in chromosome condensation.
C) They are involved in the disassembly of the nuclear envelope.
D) They are involved in migration of centrosomes to opposite sides of the nucleus.

Question

Quizplus · Accepted Answer

The phosphorylation of NEP55 and L68, which are components of the inner nuclear membrane and nuclear lamina respectively, by cyclin-dependent kinase 2 during mitosis, is most likely involved in the disassembly of the nuclear envelope. This process is crucial for allowing the mitotic spindle to access and segregate the chromosomes.

Exposure of Zebrafish Nuclei to Cytosol Isolated from Eggs at Metaphase