Study identifies distinct roles for nuclear lamin isoforms

A Northwestern Medicine study has uncovered distinct roles for major nuclear lamin isoforms in maintaining intracellular interactions and cellular mechanics, according to findings published in the Proceedings of the National ...

New protein structures to aid rational drug design

In a major advance for rational drug design, a Texas A&M AgriLife team has described several protein structures of a crucial player in cellular processes. The advance could bring new ideas for treatments of diseases such ...

How climate change stresses plants and alters their growth

Plants that inhabit the Earth have the incredible ability to grow continually for hundreds of years, and always towards the light of the sun, which provides them with the necessary energy to sprout.

Pop-up factories beneath the cell membrane

A living cell is exposed to a variety of stimuli. Countless messengers dock on its surface, where receptors in the cell membrane receive the incoming "orders." Signaling cascades are then triggered inside the cell, which ...

page 1 from 28

Cell nucleus

In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, or kernel), also sometimes referred to as the "control center", is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome. The function of the nucleus is to maintain the integrity of these genes and to control the activities of the cell by regulating gene expression--the nucleus is therefore the control center of the cell.

The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and separates its contents from the cellular cytoplasm, and the nuclear lamina, a meshwork within the nucleus that adds mechanical support, much like the cytoskeleton supports the cell as a whole. Because the nuclear membrane is impermeable to most molecules, nuclear pores are required to allow movement of molecules across the envelope. These pores cross both of the membranes, providing a channel that allows free movement of small molecules and ions. The movement of larger molecules such as proteins is carefully controlled, and requires active transport regulated by carrier proteins. Nuclear transport is crucial to cell function, as movement through the pores is required for both gene expression and chromosomal maintenance.

Although the interior of the nucleus does not contain any membrane-bound subcompartments, its contents are not uniform, and a number of subnuclear bodies exist, made up of unique proteins, RNA molecules, and particular parts of the chromosomes. The best known of these is the nucleolus, which is mainly involved in the assembly of ribosomes. After being produced in the nucleolus, ribosomes are exported to the cytoplasm where they translate mRNA.

This text uses material from Wikipedia, licensed under CC BY-SA