Thrombospondin 1

Thrombospondin 1 (TSP-1) is a protein that in humans is encoded by the THBS1 gene. It is a multi-domain glycoprotein that is secreted by various cell types and plays a significant role in cell adhesion, cell migration, cytokinesis, and angiogenesis.

Structure

Thrombospondin 1 is a large trimeric glycoprotein with a molecular weight of approximately 450 kDa. It is composed of three identical subunits, each of which is encoded by the THBS1 gene. Each subunit consists of multiple domains, including a heparin-binding domain, a procollagen homology domain, and three thrombospondin type 1 repeats (TSRs).

Function

Thrombospondin 1 is involved in a variety of biological processes. It mediates cell-to-cell and cell-to-matrix interactions and has been shown to inhibit angiogenesis by inducing apoptosis of endothelial cells. It also plays a role in immune response, wound healing, and tissue remodeling.

Clinical Significance

Alterations in the expression of Thrombospondin 1 have been associated with various diseases, including cancer, cardiovascular disease, and fibrosis. In cancer, Thrombospondin 1 can act as a tumor suppressor by inhibiting angiogenesis and tumor growth. However, some cancer cells can evade this inhibition by downregulating Thrombospondin 1 expression.

See Also

• Thrombospondin
• Angiogenesis
• Tumor suppressor