Peptide-mediated regulation: key issues

There are three sources of proteins in human body: (a) food, (b) intestinal bacteria, and (c) body cells. Any protein molecule, irrespective of its source, ends with being enzymatically digested into a number of short peptide fragments. Almost all of the fragments are but intermediates on the way to their further digesting. Only a small proportion of such fragments is implicated in regulatory processes by interacting with target cells via receptors or otherwise.

The totality of issues related to peptide-mediated regulation may be reduced to four key questions:

  1. What are the mechanisms of the synthesis of the regulatory peptides (ribosomal and/or non-ribosomal)?

  2. What cells, tissues and organs produce the regulatory peptides?

  3. How are the regulatory peptides transported through barriers (intestinal wall, cell membrane, and nuclear membrane)?

  4. What are the mechanisms of interactions of the regulatory peptides with their target cells (receptor mediated or non-receptor mediated)?