Membrane-associated protein (MAP)

Membrane-associated proteins are a broad class of proteins that are either integrated into or associated with the lipid bilayer of cells and organelles (UniProt). They are divided into integral membrane proteins, which span the hydrophobic core of the bilayer, and peripheral membrane proteins, which attach to the membrane surface through non-covalent interactions (Alberts et al., Molecular Biology of the Cell). These proteins are vital for cellular function, acting as receptors for signal transduction, channels and transporters for molecular passage, and enzymes for localized chemical reactions (Nature Reviews Drug Discovery, 2017). Because of their surface exposure and critical regulatory roles, they are the most common targets for drug development, accounting for over 50% of all FDA-approved drugs (PubMed, PMID: 28079112). Malfunctions in these proteins contribute to a wide range of diseases, such as cancer via receptor tyrosine kinases, cystic fibrosis via ion channels, and hypertension via G protein-coupled receptors (StatPearls). Therapeutic interventions typically involve small molecules or monoclonal antibodies that modulate protein activity by acting as agonists, antagonists, or inhibitors (NIH).

Other names

Membrane proteinIntegral membrane proteinPeripheral membrane proteinCell surface proteinTransmembrane protein

Drugs modulate these proteins through various mechanisms including competitive antagonism of ligands, agonism to trigger signaling, inhibition of enzymatic domains, or the blocking of ion and substrate pores to alter cellular physiology.