What is the Nuclear Envelope?

The nuclear envelope is composed of the nuclear membranes, the nuclear lamina and the nuclear pore complexes. The nuclear membranes are divided into three morphologically distinct but interconnected domains termed the inner nuclear membrane, outer nuclear membrane and pore membrane. Each of these membrane domains is associated with specific macromolecular structures. Ribosomes, that are also present on the continuous endodplasmic reticulum, are associated with the outer face of the outer nuclear membrane. The nuclear pore complexes, macromolecular structures through which transport between the nucleus and cytoplasm takes place, are associated with the pore membranes. The inner nuclear membrane is associated with the nuclear lamina, a meshwork of intermediate filament proteins termed lamins, and the heterochromatin on its nucleoplasmic face. In recent years, mutations in nuclear lamins have been shown to cause muscular dystrophy, cardiomyopathy and partial lipodystrohy.

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Nuclear envelope/Howard J. Worman, M. D./hjw14@columbia.edu