Adipocyte lipolysis pathway

The **adipocyte lipolysis pathway** refers to the series of biochemical reactions occurring primarily in adipose tissue that result in the breakdown of stored triglycerides into free fatty acids and glycerol. This process is essential for mobilizing stored energy during periods of fasting, exercise, or increased energy demand. The key steps involve sequential hydrolysis catalyzed by three main enzymes: 1. **Adipose triglyceride lipase (ATGL)** initiates hydrolysis by converting triacylglycerols to diacylglycerols. 2. **Hormone-sensitive lipase (HSL)** further breaks down diacylglycerols to monoacylglycerols. 3. **Monoglyceride lipase (MGL)** completes the process by converting monoacylglycerols to glycerol[1][2][3][4]. This cascade is tightly regulated at multiple levels: - Hormonal control via catecholamines stimulates β adrenergic receptors on adipocytes, activating adenylyl cyclase and increasing cAMP levels. - Elevated cAMP activates protein kinase A (PKA), which phosphorylates both HSL and perilipin 1A on lipid droplets. - Phosphorylation events facilitate enzyme access to lipid stores and promote coactivator interactions necessary for efficient triglyceride breakdown[2][3]. - Insulin acts antagonistically by suppressing cAMP production and thus inhibiting PKA activity[1]. Key regulatory proteins include perilipin 1A, CGI-58/ABHD5 (a coactivator), G0S2 and FSP27/CIDEC as negative regulators. Disruption of this finely tuned system contributes to metabolic diseases such as type 2 diabetes, obesity-related complications, cancer cachexia, and fatty liver disease[4]. While individual components—such as β adrenergic receptors—are considered therapeutic targets for modulating fat metabolism,[5] "adipocyte lipolysis pathway" itself is not a single molecular target but rather a complex network involving multiple proteins. **Note:** The entry "Adipocyte lipolysis pathway" does not refer to a discrete molecule/receptor but rather an entire metabolic process involving several molecular targets. For structured data purposes focused on drug discovery or pharmacology databases that require single-molecule entries with canonical names/abbreviations/mechanisms/etc., this entry should be flagged (`is_incorrect: true`) because it describes a biological process/pathway rather than an actionable molecular entity suitable for direct targeting.[1][2][3][4]

Other names

Lipolysis in adipocytesAdipose tissue lipolysisTriglyceride hydrolysis in fat cells