integrin alpha9-beta1 complex

Definition

Target type: cellularcomponent

An integrin complex that comprises one alpha9 subunit and one beta1 subunit. [PMID:12297042]

The integrin alpha9-beta1 complex is a transmembrane receptor that plays a crucial role in cell adhesion, migration, and signaling. It is a heterodimer composed of two subunits: alpha9 and beta1. The alpha9 subunit is responsible for binding to specific ligands, while the beta1 subunit interacts with intracellular signaling molecules.

**Cellular Component:**

The integrin alpha9-beta1 complex is primarily located at the **plasma membrane**, where it interacts with the extracellular matrix (ECM). The complex is also found in **focal adhesions**, which are specialized structures that anchor cells to the ECM.

**Extracellular Domain:**

The extracellular domain of the alpha9-beta1 complex consists of a series of domains that are involved in ligand binding. The alpha9 subunit contains a **beta-propeller domain** and a **thigh domain**, which are responsible for recognizing and binding to the ECM ligand **tenascin-C**. The beta1 subunit contains a **hybrid domain** and a **platelet-type integrin domain**, which are involved in dimerization with the alpha9 subunit and interactions with other ECM proteins.

**Transmembrane Domain:**

The transmembrane domain of the alpha9-beta1 complex spans the plasma membrane and connects the extracellular and intracellular domains. It is composed of hydrophobic amino acid residues that allow the complex to embed within the lipid bilayer.

**Intracellular Domain:**

The intracellular domain of the alpha9-beta1 complex interacts with a variety of intracellular signaling molecules. This domain contains a **short cytoplasmic tail** that binds to adaptor proteins, such as **talin** and **kindlin**. These adaptor proteins link the integrin complex to the cytoskeleton, providing mechanical stability and enabling signal transduction.

**Functional Roles:**

The integrin alpha9-beta1 complex plays a critical role in a variety of cellular processes, including:

- **Cell adhesion:** The complex mediates cell adhesion to the ECM by binding to tenascin-C and other ECM proteins.
- **Cell migration:** The complex facilitates cell migration by providing traction points for cells to move across the ECM.
- **Signaling:** The complex activates intracellular signaling pathways that regulate cell growth, differentiation, and survival.

**Disease Relevance:**

The integrin alpha9-beta1 complex has been implicated in a variety of diseases, including cancer, inflammatory diseases, and developmental disorders. Dysregulation of this complex can lead to abnormal cell adhesion, migration, and signaling, contributing to disease pathogenesis.'
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Proteins (1)

Compounds (17)