EMILIN2

EMILIN2 Full Name

elastin microfibril interfacer 2

EMILIN2 Introduction

EMILIN2 encodes elastin microfibril interfacer 2, a second member of the EMILIN family of extracellular matrix glycoproteins that shares the multidomain architecture of EMILIN1 but has acquired distinct expression patterns and functions. Like its relative, EMILIN2 contains an EMI domain that drives trimerization, a series of EGF-like repeats, and a C-terminal gC1q domain, and it is deposited into the extracellular matrix of tissues that contain elastic fibers, including blood vessels, muscle, and cartilage. EMILIN2 differs from EMILIN1 in its more restricted and dynamic expression and in its interactions, which include binding partners involved in cell adhesion, in the complement system, and in the regulation of cell survival. Studies have implicated EMILIN2 in the biology of the vascular and musculoskeletal systems and have revealed that it can modulate the activity of the complement pathway, connecting the extracellular matrix to innate immunity. Perhaps the most intensively studied aspect of EMILIN2 is its role in the tumor microenvironment, where it has been reported to influence the survival and death of tumor cells and to affect processes such as angiogenesis and matrix remodeling that determine whether a cancer grows and spreads. Because the extracellular matrix is increasingly recognized as an active regulator of disease rather than a passive scaffold, EMILIN2 exemplifies how individual matrix molecules can shape tissue function in health and pathology, and it is being investigated as both a biomarker and a therapeutic target.

Figure 1. EMILIN2:gene:structure,function,and pathway.

EMI-EGF-gC1q Architecture and Distinct Binding Repertoire
EMILIN2 is a secreted glycoprotein organized into an N-terminal EMI domain, a central region containing EGF-like repeats, and a C-terminal gC1q globular domain.
The EMI domain mediates the trimerization of EMILIN2, and the assembled trimer presents its globular gC1q domains for interactions with cell-surface receptors and matrix proteins.
The EMILIN2 gene is located on human chromosome 18, and although the protein shares its domain architecture with EMILIN1, its expression is controlled independently and is prominent in tissues such as the heart, skeletal muscle, and blood vessels.
The gC1q domain of EMILIN2 binds integrins and other cell-surface molecules, allowing the matrix protein to support the adhesion, spreading, and migration of cells.
Unlike EMILIN1, EMILIN2 has been found to interact with components of the complement system, and its gC1q domain can associate with the C1q protein from which the domain takes its name, suggesting a link between the matrix and innate immune surveillance.
EMILIN2 also binds proteoglycans and growth factors of the extracellular environment, and these interactions place it within the signaling networks that cells use to sense their surroundings.
Proteolytic processing and alternative splicing add further diversity to the forms of EMILIN2 that are deposited into the matrix.

Vascular Biology, Complement Crosstalk, and the Tumor Microenvironment
In blood vessels and muscle, EMILIN2 contributes to the assembly of the extracellular matrix and to the maintenance of tissue architecture, and its expression is dynamically regulated during development and in response to injury.
The interaction of EMILIN2 with the complement system suggests that matrix proteins can influence the innate immune response, potentially modulating inflammation and the clearance of damaged tissue.
In the tumor microenvironment, EMILIN2 expression is altered in several cancer types, and functional studies indicate that the protein can influence the behavior of both tumor cells and the stromal cells that support them.
Depending on the context, EMILIN2 has been reported to promote or restrain the survival of tumor cells, and it can affect the migration and invasion of malignant cells through its effects on cell adhesion and matrix remodeling.
Because the composition of the tumor matrix determines the accessibility of tumors to immune cells and to therapeutic agents, EMILIN2 is being evaluated as a biomarker of tumor progression and as a potential target for modifying the tumor microenvironment.
Ongoing research aims to define the molecular partners through which EMILIN2 exerts its effects and to determine whether manipulating the protein can improve the outcome of cancer therapy.

Alternate Names for EMILIN2

EMILIN2; elastin microfibril interfacer 2; EMILIN-2; FLJ33200; FOAP 10; Elastin microfibril interface-located protein 2; elastin microfibril interfacer 2; extracellular glycoprotein EMILIN-2; FOAP-10; Protein FOAP-10; OTTHUMP00000158648; extracellular gly