Editing Microsome (section)

== Cell-free Protein Synthesis ==

This relates to [[cell-free protein synthesis]]. Cell-free protein synthesis that is without microsomes has no way for incorporation into the microsomes to happen. This means that when microsomal membranes are presented later there isn’t the removal of the signal sequence. With microsomes there, cell-free protein synthesis demonstrates cotranslational transport of the protein into the microsome and therefore the removal of the signal sequence. This process produces a mature protein chain. Studies have looked into the cell-free protein synthesis process when microsomes have their bound ribosomes stripped away from them. This explained certain details about endoplasmic reticulum signal sequences. Normally, a [[secretory protein]] only has its signal sequence removed if the microsomes are there for [[Protein Synthesis|protein synthesis]] due to the secretory protein being incorporated into the microsomes. Protein transport doesn’t happen if there is a late addition of microsomes after the completion of the protein synthesis process.

Protein extrusion into a microsome can be described by multiple factors. A protein has been extruded if it is resistant to [[proteases]], is not resistant to proteases when detergents are present, or is glycosylated by enzymes residing in the microsomes. Additionally, another sign that a protein has been extruded is [[signal peptidase]] cleaving off the N-terminal signal peptide inside the microsome that may cause the protein to be smaller in size.