Biologically active, non membrane-anchored precursors: an overview

Area of Science:

• Biochemistry
• Cellular Biology
• Endocrinology

Background:

• Peptides act as crucial intercellular signals in multicellular organisms, mediating functions like hormones, neuromodulation, and growth.
• Biologically active peptides are synthesized from larger precursor proteins (pro-hormones) requiring post-translational modification.
• Typically, pro-hormones are inert and processed within subcellular compartments, yielding one or more bioactive peptides.

Purpose of the Study:

• To review non-membrane-anchored precursor proteins that exhibit biological activity.
• To highlight precursors that possess distinct biological functions independent of their derived peptides.
• To discuss signaling mechanisms potentially independent of the canonical receptors for generated peptides.

Main Methods:

• Literature review focusing on non-membrane-anchored biologically active precursor proteins.
• Analysis of studies detailing the independent activities and signaling pathways of these precursors.
• Comparison with established models of peptide hormone synthesis and processing.

Main Results:

• Identified a class of precursor proteins that are biologically active in their own right.
• Demonstrated that these active precursors can exert biological effects distinct from their processed peptide products.
• Observed that these precursors may utilize signaling pathways and receptors independent of those targeted by their derived peptides.
• Highlighted an exception to the general model where precursors are biologically inert.

Conclusions:

• Precursor proteins are not always biologically inert intermediates; some possess intrinsic activity.
• Active precursors offer alternative or complementary signaling mechanisms within cells and organisms.
• Understanding these non-canonical precursors broadens the scope of intercellular communication and peptide signaling research.