Multimerin-1 (MMRN1)

Multimerin-1 (MMRN1) is a large, soluble, disulfide-linked multimeric glycoprotein primarily expressed in platelets, megakaryocytes, and endothelial cells, and is a member of the EMILIN protein family. It is stored in platelet alpha granules and endothelial storage granules, released upon activation, and is not normally detectable in plasma. MMRN1 acts as a major adhesive molecule, supporting platelet adhesion and aggregate formation by binding to von Willebrand factor, fibrillar collagen (notably at GPAGPOGPX motifs), and coagulation Factor V, thereby critically influencing haemostasis, thrombosis, and vascular repair. Its functions extend to modulation of thrombin generation and adhesion of platelets and endothelial cells, and it is implicated in angiogenesis and pathological contexts such as cancer and cardiovascular disease. The molecular structure includes distinctive EMILIN-family domains, an EGF-like domain, and an RGD motif, with unclear but highly relevant roles in protein-protein interaction and vascular physiology. MMRN1 is not the same as Glycoprotein Ia (GPIa, α2β1 integrin), and aliases containing "GPIa" are likely cross-references or errors in existing nomenclature databases for this context.

Other names

Multimerin 1Multimerin-1Platelet multimerin155 kDa platelet multimerinECM EMILIN4EMILIN4MMRNElastin microfibril interfacer 4p155Endothelial cell multimerinelastin microfibril interface located protein 4EMILIN family protein

For drugs affecting coagulation or platelet activation: may indirectly affect MMRN1 release, function, or its interactions with Factor V and von Willebrand factor. No drugs known to use direct MMRN1 inhibition or activation as a primary mechanism.