Hormone-sensitive lipase must mediate the hydrolysis of not only triacyl glycerol stored in adipose tissue but also cholesterol esters in the adrenal glands, ovaries, testes, and macrophages (Holm, 2003 ). For those who lack HSL it is the breakdown of cellular fat reserves which fuels energy production and multiple anabolic processes (Zechner & Langin, 2014). HSL is the major enzyme of fatty acid mobilase from acylglycerols in adipocytes to nonadipocytes. In adipocytes, catecholamines function for lipolysis primarily through protein kinase. A mediated phosphorylation of HSL and perilipin, a protein that coats the lipid droplet. The antilipolytic action of insulin is mainly mediated by the lowering of CAMP levels, obtained through the activation of phosphodiesterase 3B (Osuga et al., 2000). Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essaySo, HSL alone catalyzes the hydrolysis of triglycerides and diglycerides, while the participation of monoglyceride lipase is required to achieve complete hydrolysis of monoglycerides. HSL and monoglyceride lipase appear to play a key role in the hydrolysis of acylglycerols even in non-adipocytes, but the involvement of additional lipases can be expected (Holm, 2003). It is encoded by a gene located on chromosome 19 and has no homology to members of the pancreatic lipase gene family such as lipoprotein lipase (LPL). The lipolytic activities of HSL are under acute neuronal and hormonal control. Catecholamines and other lipolytic hormones stimulate these activities through reversible serine phosphorylation by cyclic adenosine 39,59-monophosphate (cAMP)-dependent protein kinase (PKA). In contrast, insulin, an antilipolytic hormone, suppresses its activities by preventing phosphorylation (Osuga et al., 2000). Therefore, it is believed that the activation of this enzyme in adipose tissues explains the increase in plasma levels of free fatty acids (FFA) in the blood. various conditions such as starvation or diabetes mellitus. Since mice lacking the β3-adrenergic receptor, a dominant form of β-adrenergic receptor expressed in adipocytes, are obese, and since mice lacking the RIIb subunit of PKA are lean due to increased PKA activity, it is reasonable to hypothesize that l 'HSL mediates the regulation of the b3-adrenergic receptor. adiposity via the adrenergic signaling pathway (Zechner & Langin, 2014). The studies reported below were undertaken in an attempt to characterize and study hormone-sensitive lipase activity in adipose tissue without interference from other lipases. By setting up appropriate assay conditions, I was able to measure a lipase activity that apparently reflects quite well the hormone-sensitive lipolytic activity of intact tissue (Vaughan, Berger, & Steinberg, 1964). Remember: This is just a sample Get a custom paper from our expert writers now. Get a Custom Essay The structure and biochemistry of hormone-sensitive lipase is located on chromosome 19q13.3 and was initially described as containing 9 exons spanning approximately 11 and 10 kB in humans and mice, respectively. encode a 2.8 kB mRNA. Subsequently, two additional exons (named A and B) differentially encoding 170 and 70 nt untranslated regions were identified approximately 12.5 and 1.5 kB upstream of exon 1, respectively. Only the smallest product of HSL mRNA is expressed in human adipose tissue. In contrast, five different exons have been reported within 7 kB of the exon 1 translation start site in mouse HSL, each, 2002).