Lipolysis: more than just a lipase.
Successful adaptation to starvation in mammals depends heavily on the regulated mobilization of fatty acids from triacylglycerols stored in adipose tissue. Although it has long been recognized that cyclic AMP represents the critical second messenger and hormone-sensitive lipase (HSL)**Abbreviations used in this paper: ADRP, adipocyte differentiation-related protein; HSL, hormone-sensitive lipase; PKA, protein kinase A; TAG, triacylglycerol. the rate-determining enzyme for lipolysis, simple activation of the enzyme has failed to account for the robust augmentation of fatty release in response to physiological agonists. In this issue, Sztalryd et al. (2003) provide convincing support to the notion that the subcellular compartmentalization of lipase also regulates lipolysis, and, more importantly, that proteins other than HSL are localized to the lipid droplet and are indispensable for its optimal hydrolysis.
Birnbaum
Morris J
MJ
Morris J. Birnbaum, Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, 415 Curie Blvd., Room 322 CRB, Philadelphia, PA 19104, USA. birnbaum@mail.med.upenn.edu
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D002451:Cell Compartmentation / Q000502:physiology*; D006801:Humans; D050356:Lipid Metabolism; D008066:Lipolysis / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology; D002787:Sterol Esterase / Q000378:metabolism*
D002787:Sterol Esterase