Specifically, the rough endoplasmic reticulum (RER) is directly connected to the nuclear envelope. The RER is studded with ribosomes, which are responsible for protein synthesis. The nuclear envelope is a double membrane that surrounds the nucleus and controls what enters and exits.

Here's how it works:

* mRNA transcripts are made in the nucleus and move through the nuclear pores into the cytoplasm.

* The mRNA then binds to ribosomes on the RER, where protein synthesis occurs.

* The newly synthesized proteins can then be folded, modified, and transported through the ER network.

This connection between the nucleus and ER is crucial for the efficient production and processing of proteins within the cell.