Rho-associated protein kinase

Rho-associated protein kinase

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3D structure of Rho-associated protein kinase

Rho-associated protein kinase (ROCK) is a serine/threonine-specific protein kinase that is involved in regulating the shape and movement of cells by acting on the cytoskeleton. It is a major downstream effector of the small GTPase RhoA, which is part of the Rho family of GTPases. ROCK plays a crucial role in various cellular functions, including contraction, motility, proliferation, and apoptosis.

Structure

ROCK is a dimeric enzyme composed of two isoforms: ROCK1 and ROCK2. Both isoforms share a high degree of homology and consist of an N-terminal kinase domain, a coiled-coil region containing a Rho-binding domain, and a C-terminal pleckstrin homology domain. The kinase domain is responsible for the enzyme's catalytic activity, while the Rho-binding domain allows ROCK to interact with activated RhoA.

Function

ROCK is involved in the regulation of the actin cytoskeleton, which is essential for maintaining cell shape and enabling cell movement. It phosphorylates various downstream targets, including myosin light chain (MLC) and LIM kinase, leading to increased actin-myosin contractility and stabilization of actin filaments. This activity is crucial for processes such as cell migration, adhesion, and cytokinesis.

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Function of ROCK in cellular processes

Role in Disease

ROCK has been implicated in a variety of diseases due to its role in cell motility and proliferation. It is involved in the pathogenesis of cardiovascular diseases, such as hypertension and atherosclerosis, by affecting vascular smooth muscle contraction and endothelial cell function. In cancer, ROCK contributes to tumor cell invasion and metastasis by promoting changes in the cytoskeleton that facilitate cell movement.

Therapeutic Target

Given its involvement in numerous pathological conditions, ROCK is considered a potential therapeutic target. Inhibitors of ROCK, such as fasudil and Y-27632, have been developed and are being investigated for their efficacy in treating diseases like glaucoma, pulmonary hypertension, and cancer. These inhibitors work by blocking the kinase activity of ROCK, thereby reducing abnormal cell contraction and proliferation.

Related pages

• Rho family of GTPases
• Cytoskeleton
• Protein kinase
• Cell migration