ANGPTL4

Overview of the ANGPTL4 protein

Overview

ANGPTL4 (Angiopoietin-like 4) is a protein that in humans is encoded by the ANGPTL4 gene. It is a member of the angiopoietin-like protein family, which is involved in various physiological processes including lipid metabolism, glucose homeostasis, and angiogenesis.

Structure

ANGPTL4 is a secreted glycoprotein that consists of an N-terminal coiled-coil domain and a C-terminal fibrinogen-like domain. The protein undergoes proteolytic cleavage, resulting in the separation of these two domains, which can function independently.

Function

ANGPTL4 plays a crucial role in the regulation of lipid metabolism. It inhibits lipoprotein lipase (LPL), an enzyme responsible for the hydrolysis of triglycerides in lipoproteins, thereby modulating the levels of circulating triglycerides. ANGPTL4 is also involved in the regulation of glucose homeostasis and has been implicated in the development of insulin resistance.

Role in Angiogenesis

In addition to its metabolic functions, ANGPTL4 is involved in the regulation of angiogenesis, the process of new blood vessel formation. It can act as both a pro-angiogenic and anti-angiogenic factor depending on the context, influencing tumor growth and metastasis.

Clinical Significance

Alterations in ANGPTL4 expression and function have been associated with various metabolic disorders, including hyperlipidemia, obesity, and type 2 diabetes. It is also being studied for its potential role in cancer progression and as a therapeutic target for metabolic and cardiovascular diseases.

Regulation

The expression of ANGPTL4 is regulated by several factors, including peroxisome proliferator-activated receptors (PPARs), hypoxia, and fasting. These factors influence its expression in different tissues, such as the liver, adipose tissue, and muscle.

Research Directions

Ongoing research is focused on understanding the precise mechanisms by which ANGPTL4 regulates lipid and glucose metabolism, as well as its role in disease states. There is also interest in developing therapeutic agents that target ANGPTL4 for the treatment of metabolic and cardiovascular diseases.

Related pages

• Lipoprotein lipase
• Angiogenesis
• Metabolic syndrome
• Insulin resistance

Gallery

• 
  Diagram of ANGPTL4 structure and function