Answer to Question #153621 in Cell Biology for Henry Coleman

Question

Explain how the nucleus, mitichondria, ribosome, endoplasmic reticulum, and Golgi body work to produce lysosomes within a macrophage to enable it to fight infection

Answer 1

The transcription factor EB (TFEB) controls the nucleus to transcribe lysosomal protein genes. These mRNA-transcripts then leave the nucleus to enter the cytosol. The cell mitochondria synthesizes energy to aid in the process. Ribosomes in the nucleus translate the transcripts into nascent peptide chains. The chains translocate into the rough endoplastic reticulum where they undergo modification into lysosomal soluble proteins. These proteins are recruited by the EGRESS complex to exit the rough endoplasmic reticulum through COPII-coated vesicles.

The proteins, which are now lysosomal soluble enzymes are delivered by the COPII vesicles to the Golgi apparatus. Here, they acquire a specific lysosome tag called mannose 6-phosphate. This tag allows the protein to bind to mannose 6-phosphate receptors in the Golgi apparatus. The phenomenal is important for proper packaging into lysosomal system vesicles.

A section of the cell membrane pinches off to be internalized by the cell. This process is called endocytosis and the cell membrane section is called endosome. The endosomes mature into late endosomes that fuse with the lysosomal enzyme-filled vesicles from the Golgi apparatus. Once the fusion takes place, the late endosomes eventually develop into mature lysosomes.