CD109 molecule | Elisa - Clia - Antibody - Protein

Background

CD109 is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein that is a member of the alpha-2-macroglobulin/complement family. It is encoded by the CD109 gene and is widely expressed in a variety of cell types, including activated T-cells, platelets, endothelial cells, and certain epithelial cells. CD109 plays a critical role in the regulation of the immune system and cellular responses to growth factors. It is involved in various biological processes, such as cell proliferation, immune response modulation, and tumor suppression.

Protein Structure

• Domain Composition: CD109 consists of several domains including a large N-terminal alpha-macroglobulin domain, a middle von Willebrand factor type A (vWFA) domain, and a C-terminal GPI anchor site.
• GPI Anchor: This post-translational modification allows CD109 to attach to the cell membrane, facilitating its interactions with other cell surface proteins and the extracellular matrix.
• Glycosylation Sites: CD109 is heavily glycosylated, which is critical for its stability and function.

Classification and Subtypes

CD109 is classified under the alpha-2-macroglobulin family due to its structural and functional characteristics. There are no known subtypes of CD109, but it shares significant homology with other members of the alpha-2-macroglobulin family, indicating conserved functions across this protein family.

Function and Biological Significance

• TGF-β Signaling Regulation: CD109 negatively regulates the TGF-β signaling pathway, which is crucial for controlling cell growth, differentiation, and immune responses. By binding to TGF-β receptors, CD109 prevents TGF-β from activating its downstream signaling pathways.
• Immune Response: CD109 plays a role in modulating immune responses, particularly in T-cell activation and proliferation. It helps regulate the balance between immune tolerance and activation, which is essential for maintaining immune homeostasis.
• Wound Healing and Angiogenesis: CD109 is involved in wound healing processes and the formation of new blood vessels (angiogenesis), making it an important factor in tissue repair and regeneration.
• Cancer: CD109 has been implicated in tumor suppression. Its expression is often downregulated in various cancers, suggesting a role in inhibiting tumor growth and progression.

Clinical Issues

• Cancer: Altered expression of CD109 has been observed in various cancers, including squamous cell carcinoma and glioblastoma. It is being studied as a potential biomarker for diagnosis and prognosis in cancer patients.
• Immune Disorders: Dysregulation of CD109 can lead to immune system imbalances, contributing to autoimmune diseases or chronic inflammatory conditions.
• Therapeutic Potential: Targeting CD109 or modulating its activity offers potential therapeutic strategies for treating cancers and fibrotic diseases, where TGF-β signaling plays a pathogenic role.

Summary

CD109 is a multifunctional GPI-anchored glycoprotein involved in the regulation of TGF-β signaling, immune responses, and tissue repair. Structurally, it features multiple domains essential for its function and interactions. It plays significant roles in various physiological and pathological processes, including cancer and immune regulation. Understanding CD109's mechanisms and effects offers insights into potential therapeutic targets for treating related diseases.