Question

During mitosis, the nuclear envelope fragments as the chromosomes condense, then reassembles around the two new nuclei of each daughter cell. The intermediate filaments called lamins, play a major role in controlling this process. How is lamin ""collapse"" or fragmentation regulated?

-motor proteins pul the filaments apart
-GTP binds to the lamin proteins
-lamin proteins are phosphorylated by activated kinases
-calcium ions are released from the endoplasmic reticulum and bind to the lamin proteins causing collapse

Answer 1

Lamin collapse during mitosis is regulated by the phosphorylation of lamin proteins by activated kinases, facilitating the breakdown of the nuclear envelope as the cell prepares to separate chromosomes.

Step-by-step explanation:

The process of lamin collapse or fragmentation during mitosis is regulated by the phosphorylation of lamin proteins by activated kinases. During the early stages of mitosis, specifically prophase, the nuclear envelope begins to disintegrate into small vesicles to allow the mitotic spindle to access the separated chromosomes. This disintegration is facilitated by the phosphorylation of the nuclear lamins, which causes the nuclear envelope to become more fluid and disperse into vesicles, allowing for the distribution of the chromosomes to opposite poles of the cell during mitosis.