positive regulation of triglyceride lipase activity
Definition
Target type: biologicalprocess
Any process that increases the activity of triglyceride lipase. [GOC:dph]
Positive regulation of triglyceride lipase activity is a critical process in the breakdown and mobilization of stored triglycerides, primarily in adipose tissue. This process is tightly regulated to ensure proper energy homeostasis and maintain lipid levels within a healthy range.
**Key players:**
* **Triglyceride lipases:** Enzymes responsible for the hydrolysis of triglycerides into glycerol and free fatty acids. Major lipase involved in this process include:
* **Hormone-sensitive lipase (HSL):** The primary lipase responsible for triglyceride breakdown in adipose tissue. Its activity is stimulated by hormones like glucagon and epinephrine and inhibited by insulin.
* **Lipoprotein lipase (LPL):** Found in tissues like adipose tissue, heart, and skeletal muscle, it breaks down triglycerides from lipoproteins (e.g., chylomicrons and very-low-density lipoproteins).
* **Hormones and signaling molecules:**
* **Glucagon:** A hormone released by the pancreas in response to low blood glucose levels. It activates HSL through phosphorylation, promoting triglyceride breakdown and releasing fatty acids into circulation.
* **Epinephrine:** A hormone secreted by the adrenal glands in response to stress. Like glucagon, it activates HSL, leading to increased triglyceride breakdown and energy mobilization.
* **Insulin:** A hormone released by the pancreas in response to high blood glucose levels. It inhibits HSL activity, promoting triglyceride storage and reducing lipolysis.
* **Other signaling molecules:** Factors like AMP-activated protein kinase (AMPK), a key regulator of energy metabolism, can also influence triglyceride lipase activity.
**Mechanism of regulation:**
1. **Hormonal regulation:** Hormones like glucagon and epinephrine bind to their respective receptors on adipose cells. This binding triggers a signaling cascade that activates protein kinase A (PKA).
2. **Activation of HSL:** PKA phosphorylates HSL, leading to its activation. Activated HSL then hydrolyzes triglycerides into glycerol and free fatty acids.
3. **Insulin inhibition:** Insulin, on the other hand, activates a signaling pathway that inhibits PKA, thus reducing HSL phosphorylation and its activity.
4. **Other regulatory mechanisms:** Several other mechanisms, including intracellular calcium levels, protein-protein interactions, and post-translational modifications like ubiquitination, contribute to the regulation of triglyceride lipase activity.
**Significance:**
* **Energy mobilization:** Positive regulation of triglyceride lipase activity allows for the release of stored energy (free fatty acids) during periods of fasting, exercise, or stress.
* **Lipid metabolism:** Proper regulation of lipolysis ensures that lipid levels are maintained within a healthy range, preventing the accumulation of excess triglycerides in tissues.
* **Metabolic disorders:** Disruption of this process can lead to metabolic disorders such as obesity, insulin resistance, and type 2 diabetes.
This complex interplay of hormones, signaling molecules, and enzyme activity ensures the efficient and balanced utilization of stored triglycerides, contributing to overall energy homeostasis and metabolic health.'
"
Proteins (1)
Protein | Definition | Taxonomy |
---|---|---|
Pancreatic triacylglycerol lipase | A pancreatic triacylglycerol lipase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P16233] | Homo sapiens (human) |
Compounds (5)
Compound | Definition | Classes | Roles |
---|---|---|---|
salvin | salvin: a biocyclic diterpenoid; from sage and rosemary (Lamiaceae) | abietane diterpenoid; carbotricyclic compound; catechols; monocarboxylic acid | angiogenesis modulating agent; anti-inflammatory agent; antineoplastic agent; antioxidant; apoptosis inducer; food preservative; HIV protease inhibitor; plant metabolite |
Koenimbine | koenimbin: has antineoplastic activity; isolated from curry leaf, Murraya koenigii; structure in first source | carbazoles | |
mahanimbine | mahanimbine: from Murraya koenigii leaves; structure in first source | carbazoles | |
carnosol | carnosol: isolated from Lepechinia hastata | diterpenoid | |
orlistat | orlistat : A carboxylic ester resulting from the formal condensation of the carboxy group of N-formyl-L-leucine with the hydroxy group of (3S,4S)-3-hexyl-4-[(2S)-2-hydroxytridecyl]oxetan-2-one. A pancreatic lipase inhibitor, it is used as an anti-obesity drug. Orlistat: A lactone derivative of LEUCINE that acts as a pancreatic lipase inhibitor to limit the absorption of dietary fat; it is used in the management of obesity. | beta-lactone; carboxylic ester; formamides; L-leucine derivative | anti-obesity agent; bacterial metabolite; EC 2.3.1.85 (fatty acid synthase) inhibitor; EC 3.1.1.3 (triacylglycerol lipase) inhibitor |