GO:1990972 multimerin complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1990972 (multimerin complex) is a glycoprotein complex of the C1q/TNF superfamily involved in cell adhesion, defined as a homotrimer that can assemble into supramolecular Multimerin structures.
• Multimerin-1 (MMRN1) is stored in platelet alpha-granules and endothelial cells, where it binds factor V and participates in hemostasis.
• Multimerin-2 (MMRN2, also known as EMILIN-3) forms a complex with CD93 and β1 integrin in endothelial cells, regulating adhesion and migration.
• The EMILIN/Multimerin family shapes cancer progression, angiogenesis, and extracellular matrix remodeling.
• Storage pool defects such as gray platelet syndrome affect multimerin-1 and factor V storage without altering proteolytic processing.
• CRISPR knockout, knock-in, and overexpression models are essential to dissect multimerin complex gene function in platelets and endothelium.
Description
The multimerin complex (GO:1990972) is a glycoprotein assembly of the C1q/TNF superfamily that mediates cell adhesion and forms supramolecular structures through homotrimerization. First identified as a platelet alpha-granule protein, multimerin-1 (MMRN1) was discovered in the early 1990s and has since been recognized as a unique component of platelet and endothelial cell biology. The complex is defined by its ability to self-assemble into large multimeric structures, a property shared with other C1q/TNF family members such as EMILINs. Researchers study GO:1990972 to understand hemostasis, vascular biology, and extracellular matrix organization, as well as to identify therapeutic targets in bleeding disorders and cancer. The multimerin complex is not a single protein but a dynamic assembly that includes multimerin-1, multimerin-2, and associated factors such as factor V and CD93/β1 integrin. Its relevance spans platelet storage granule defects, endothelial cell migration, and tumor microenvironment remodeling.
multimerin complex At A Glance
| GO ID | GO:1990972 |
|---|---|
| GO term | multimerin complex |
| Ontology | cellular_component |
| Synonym | Elastic microfibrillar interface 3 complex, Elastic microfibrillar interface 4 complex, EMILIN-3 complex, EMILIN-4 complex, Multimerin-1 complex, Multimerin-2 complex, p155 complex, Platelet glycoprotein Ia* complex |
| Major function | Cell adhesion and supramolecular assembly |
| Family | C1q/TNF superfamily |
| Subunit structure | Homotrimer that forms supramolecular structures |
| Cellular location | Platelet alpha-granules, endothelial cells, extracellular matrix |
What Is GO:1990972?
According to the Gene Ontology, GO:1990972 (multimerin complex) is a glycoprotein complex of the C1q/TNF superfamily involved in cell adhesion. It is defined as a homotrimer that will combine to form supramolecular Multimerin structures. The complex includes members such as multimerin-1, multimerin-2 (EMILIN-3), EMILIN-4, and platelet glycoprotein Ia*, and is synonymous with elastic microfibrillar interface complexes.
Why Is multimerin complex Important in Cell Biology?
The multimerin complex is critical for platelet function, hemostasis, and vascular biology, and its dysfunction is linked to bleeding disorders and cancer progression. Understanding its assembly and interactions provides insights into extracellular matrix remodeling and cell adhesion mechanisms that are fundamental to both normal physiology and disease.
• Regulates platelet alpha-granule storage and release of factor V.
• Mediates endothelial cell adhesion and migration through CD93/β1 integrin.
• Involved in hemostasis and thrombosis via factor V binding.
• Implicated in gray platelet syndrome and storage pool deficiencies.
• Shapes cancer landscape through EMILIN/Multimerin family functions.
• Provides a model for C1q/TNF superfamily supramolecular assembly.
• Potential biomarker for vascular and bleeding disorders.
• Target for anti-angiogenic and anti-tumor strategies.
What Happens During multimerin complex?
Biosynthesis and homotrimerization
In simple terms: The complex is built from three identical protein chains that twist together.
Multimerin-1 is synthesized in megakaryocytes and endothelial cells as a large glycoprotein that undergoes homotrimerization via its C1q/TNF domain. This trimer serves as the building block for higher-order supramolecular structures.
Storage in alpha-granules
In simple terms: The complex is packed into tiny storage sacs inside platelets.
In resting platelets, multimerin-1 is stored in alpha-granules along with factor V, and it colocalizes with factor V in these granules. Storage defects such as gray platelet syndrome affect multimerin-1 storage without altering its proteolytic processing.
Secretion and extracellular assembly
In simple terms: When platelets activate, the complex is released to form networks outside cells.
Upon platelet activation, multimerin-1 is secreted and can assemble into supramolecular multimerin structures that participate in cell adhesion and matrix organization. The complex interacts with factor V, and the MMRN1 binding region within the factor V C2 domain has been mapped.
Endothelial cell adhesion and migration
In simple terms: In blood vessels, the complex helps cells stick and move.
Multimerin-2 (EMILIN-3) forms a complex with CD93 and β1 integrin in endothelial cells, and the small GTPase Rab5c regulates trafficking of this complex during adhesion and migration. This function is critical for angiogenesis and vascular remodeling.
Key Genes Involved in GO:1990972 multimerin complex
The following genes encode proteins that are components or interactors of the multimerin complex (GO:1990972).
| Gene | Major Role | Research Relevance |
|---|---|---|
| MMRN1 | Encodes multimerin-1, the founding member of the complex | Platelet alpha-granule storage, factor V binding, bleeding disorders |
| MMRN2 | Encodes multimerin-2 (EMILIN-3), endothelial complex component | Endothelial adhesion, CD93/β1 integrin trafficking, angiogenesis |
| EMILIN3 | Alternative name for multimerin-2 | C1q/TNF family member in elastic microfibrils |
| EMILIN4 | Encodes EMILIN-4, a related complex component | Supramolecular assembly, extracellular matrix |
| F5 | Factor V, binds multimerin-1 in alpha-granules | Hemostasis, platelet storage pool defects |
| CD93 | Forms complex with multimerin-2 and β1 integrin | Endothelial cell adhesion and migration |
| ITGB1 | β1 integrin, partner in CD93/multimerin-2 complex | Cell adhesion, signaling |
| RAB5C | Small GTPase regulating trafficking of the complex | Endosomal trafficking in endothelial cells |
| GP1BA | Platelet glycoprotein Ia* complex component | Platelet adhesion, von Willebrand factor receptor |
| MMRN1 | p155 complex synonym | Historical name for multimerin-1 |
| MMRN2 | EMILIN-3 complex synonym | Vascular biology |
| EMILIN1 | Related C1q/TNF family member | Elastic fiber assembly, cancer |
| EMILIN2 | Related C1q/TNF family member | Angiogenesis, tumor suppression |
| COLQ | C1q/TNF family member | Neuromuscular junction, not directly in multimerin complex |
| C1QA | C1q/TNF superfamily prototype | Complement system, structural comparison |
| ADAMTS13 | Interacts with multimerin-1 in platelet release | Thrombotic thrombocytopenic purpura |
| VWF | Von Willebrand factor, colocalizes with multimerin-1 | Hemostasis, platelet adhesion |
How Is multimerin complex Regulated?
The multimerin complex is regulated at multiple levels. Rab5c GTPase controls trafficking of the CD93/multimerin-2/β1 integrin complex in endothelial cells. In platelets, storage pool defects such as gray platelet syndrome and alpha-delta-storage pool deficiency affect alpha-granule factor V and multimerin storage without altering proteolytic processing. The MMRN1 binding region within the factor V C2 domain mediates complex formation, providing a regulatory interface. Additionally, the EMILIN/Multimerin family is subject to transcriptional and post-translational regulation in cancer.
multimerin complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| MMRN1 | Gray platelet syndrome, storage pool deficiency | MMRN1 knockout megakaryocytic cell line |
| MMRN2 | Angiogenesis, tumor vascularization | MMRN2 knockout endothelial cells |
| F5 | Factor V deficiency, bleeding | F5 point mutation knock-in in platelets |
| CD93 | Endothelial migration defects | CD93 knockout mouse or HUVEC model |
| RAB5C | Trafficking defects in endothelium | RAB5C dominant-negative overexpression |
Bleeding disorders and platelet storage pool defects
Multimerin-1 is stored in platelet alpha-granules, and storage defects in gray platelet syndrome and alpha-delta-storage pool deficiency affect alpha-granule factor V and multimerin storage without altering their proteolytic processing. Abnormalities in multimerin-1 have been linked to bleeding disorders, and its interaction with factor V is critical for hemostasis.
Cancer and tumor microenvironment
The EMILIN/Multimerin family shapes the cancer landscape by influencing extracellular matrix remodeling, angiogenesis, and cell adhesion. Multimerin-2 (EMILIN-3) in endothelial cells may affect tumor vascularization through its role in CD93/β1 integrin trafficking.
Vascular and endothelial dysfunction
The CD93/multimerin-2/β1 integrin complex is regulated by Rab5c and is essential for endothelial cell adhesion and migration, processes that are dysregulated in vascular diseases and angiogenesis.
From multimerin complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does MMRN1 loss affect platelet alpha-granule storage? | MMRN1 knockout megakaryocytic cell line (KO) |
| How does MMRN2 point mutation affect CD93 binding? | MMRN2 point mutation knock-in endothelial cells |
| Can tagged MMRN1 track supramolecular assembly? | Tagged knock-in MMRN1 in platelets |
| Does MMRN2 overexpression alter angiogenesis? | MMRN2 overexpression in HUVECs |
| Which genes regulate multimerin complex trafficking? | CRISPR library screening in endothelial cells |
| Does factor V C2 domain mutation disrupt MMRN1 binding? | F5 point mutation knock-in |
| Is multimerin-1 required for factor V storage? | MMRN1 knockout mouse model |
How to Study the multimerin complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Co-IP/MS | Protein-protein interactions | Identify multimerin complex partners |
| Immunofluorescence | Subcellular localization | Alpha-granule storage of multimerin-1 |
| CRISPR knockout | Gene function loss | Test MMRN1/MMRN2 roles in adhesion |
| RNA-seq | Gene expression | EMILIN/Multimerin family profiling in cancer |
| Western blot | Protein levels and processing | Storage pool defect analysis |
| ELISA | Quantitative protein binding | Factor V-multimerin interaction |
| Live-cell imaging | Trafficking dynamics | Rab5c regulation of CD93 complex |
| Bioinformatics | Sequence and structure analysis | C1q/TNF domain conservation |
Proteomics and co-immunoprecipitation
Co-immunoprecipitation coupled with mass spectrometry can identify multimerin complex components and interactors such as factor V and CD93/β1 integrin.
Imaging and colocalization
Immunofluorescence and electron microscopy can visualize multimerin-1 storage in platelet alpha-granules and its colocalization with factor V.
CRISPR screening and functional genomics
Genome-wide CRISPR knockout screens in endothelial cells can identify regulators of multimerin-2 trafficking and adhesion.
Transcriptomics and bioinformatics
RNA-seq and bioinformatic analysis of EMILIN/Multimerin family expression across cancers can reveal disease associations.
How CRISPR Can Be Used to Study GO:1990972 multimerin complex
Knockout
CRISPR knockout of MMRN1 or MMRN2 in megakaryocytic or endothelial cell lines can reveal loss-of-function phenotypes in granule storage and cell adhesion.
Point Mutation
Point mutations in the factor V C2 domain or MMRN2 CD93-binding interface can be introduced to dissect binding specificity and complex assembly.
Knock-in
Tagged knock-in of MMRN1 (e.g., GFP or HA) allows tracking of supramolecular assembly and trafficking in primary cells.
Overexpression
Overexpression of MMRN2 or EMILIN family members in endothelial cells can test gain-of-function effects on angiogenesis and migration.
How EDITGENE Supports multimerin complex Research
Researchers studying multimerin complex-related genes often need to determine whether a candidate gene is causally involved in platelet storage, endothelial adhesion, or cancer progression. EDITGENE provides CRISPR-based cell models and screening services to accelerate this discovery.
Contact EDITGENE today to design your custom CRISPR model for multimerin complex research.
Frequently Asked Questions About multimerin complex
What is GO:1990972 multimerin complex?
GO:1990972 is a glycoprotein complex of the C1q/TNF superfamily involved in cell adhesion, defined as a homotrimer that forms supramolecular Multimerin structures.
What genes are involved in multimerin complex?
Key genes include MMRN1, MMRN2 (EMILIN-3), EMILIN4, F5, CD93, ITGB1, and RAB5C.
Where is multimerin complex found?
It is found in platelet alpha-granules, endothelial cells, and extracellular matrix.
What is the function of multimerin-1?
Multimerin-1 is stored in platelet alpha-granules, binds factor V, and participates in hemostasis.
How is multimerin complex related to disease?
It is linked to gray platelet syndrome, storage pool defects, and cancer progression.
What is multimerin-2?
Multimerin-2 (EMILIN-3) forms a complex with CD93 and β1 integrin in endothelial cells, regulating adhesion and migration.
How can I study multimerin complex in the lab?
Use CRISPR knockout, knock-in, overexpression, co-IP, imaging, and CRISPR screening.
Does multimerin complex bind factor V?
Yes, multimerin-1 binds factor V in platelet alpha-granules, and the binding region is within the factor V C2 domain.
What are synonyms for multimerin complex?
Synonyms include EMILIN-3 complex, EMILIN-4 complex, Multimerin-1 complex, Multimerin-2 complex, p155 complex, and Platelet glycoprotein Ia* complex.
Is multimerin complex involved in cancer?
Yes, the EMILIN/Multimerin family shapes the cancer landscape through extracellular matrix remodeling and angiogenesis.
Conclusion
The multimerin complex (GO:1990972) is a unique C1q/TNF superfamily assembly that bridges platelet biology, endothelial adhesion, and extracellular matrix organization. Its components, including multimerin-1, multimerin-2, and factor V, are critical for hemostasis and vascular function, and their dysregulation contributes to bleeding disorders and cancer. Continued research using CRISPR models and advanced proteomics will further illuminate its supramolecular assembly and therapeutic potential.
References
- 1. Hayward CP et al.. 1995. Multimerin.. Curr Opin Hematol 2(5):339-44 PMID: 9372017
- 2. Hayward CP. 1997. Multimerin: a bench-to-bedside chronology of a unique platelet and endothelial cell protein--from discovery to function to abnormalities in disease.. Clin Invest Med 20(3):176-87 PMID: 9189649
- 3. Hayward CP et al.. 1993. Multimerin is found in the alpha-granules of resting platelets and is synthesized by a megakaryocytic cell line.. J Clin Invest 91(6):2630-9 PMID: 8514871
- 4. Barbera S et al.. 2019. The small GTPase Rab5c is a key regulator of trafficking of the CD93/Multimerin-2/β1 integrin complex in endothelial cell adhesion and migration.. Cell Commun Signal 17(1):55 PMID: 31138217
- 5. Hayward CP et al.. 1995. Factor V is complexed with multimerin in resting platelet lysates and colocalizes with multimerin in platelet alpha-granules.. J Biol Chem 270(33):19217-24 PMID: 7642592
- 6. Jeimy SB et al.. 2004. Identification of the MMRN1 binding region within the C2 domain of human factor V.. J Biol Chem 279(49):51466-71 PMID: 15452129
- 7. Hayward CP et al.. 2001. The storage defects in grey platelet syndrome and alphadelta-storage pool deficiency affect alpha-granule factor V and multimerin storage without altering their proteolytic processing.. Br J Haematol 113(4):871-7 PMID: 11442477
- 8. Poletto E et al.. 2026. Behind the scenes: how the EMILIN/Multimerin family shapes the cancer landscape.. FEBS J 293(13):3991-4013 PMID: 41194556
