Endocrine control of TAG lipase in the fat body of the migratory locust, Locusta migratoria

Auerswald, Lutz; GÄde, Gerd

doi:10.1016/j.ibmb.2006.07.004

Cited by 35 publications

(25 citation statements)

References 31 publications

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“…As mentioned above, AKH-induced activation of the cytosolic TG-lipase activity has been reported in several insects including moth (10), beetle (16), and locust (15). This mechanism of activation, which is independent of the phosphorylation state of TGL, remains to be elucidated.…”

Section: Hormonal Regulation Of Fat Body Energy Mobilizationmentioning

confidence: 79%

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Insect Fat Body: Energy, Metabolism, and Regulation

Arrese¹,

Soulages²

2010

Annu. Rev. Entomol.

1,925

1,547

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The fat body plays major roles in the life of insects. It is a dynamic tissue involved in multiple metabolic functions. One of these functions is to store and release energy in response to the energy demands of the insect. Insects store energy reserves in the form of glycogen and triglycerides in the adipocytes, the main fat body cell. Insect adipocytes can store a great amount of lipid reserves as cytoplasmic lipid droplets. Lipid metabolism is essential for growth and reproduction and provides energy needed during extended nonfeeding periods. This review focuses on energy storage and release and summarizes current understanding of the mechanisms underlying these processes in insects. INSECT FAT BODY: AN OVERVIEWThe insect fat body plays an essential role in energy storage and utilization. It is the central storage depot for excess nutrients. In addition, it is an organ of great biosynthetic and metabolic activity (77). Fat body cells not only control the synthesis and utilization of energy reserves-fat and glycogen-but also synthesize most of the hemolymph proteins and circulating metabolites. Large amounts of relevant proteins, such as storage proteins used as an amino acid reservoir for morphogenesis, lipophorins responsible for the lipid transport in circulation, or vitellogenins for egg maturation, are secreted by the fat body (74). Most of the insect's intermediary metabolism takes place in this organ, including lipid and carbohydrate metabolism, protein synthesis, and amino acid and nitrogen metabolism. Some metabolic processes are stage specific such as the synthesis and secretion of storage proteins into the hemolymph that occur in the feeding larva or the synthesis of vitellogenin in adult insects.To perform multiple metabolic functions to fulfill the changing physiological needs of the insect during development, the fat body must be able to integrate signals from other organs. Many of these functions are hormonally regulated, and thus the fat body is the target organ of several hormones (47,107). At the same time, the fat body responds to the metabolic requirements of the organ itself. Therefore, several metabolic processes in the fat body must be tightly coupled to a number of metabolic pathways.Physiological systems to sense nutrient reserves are expected in all organisms, and in insects nutrient sensing itself appears to be the domain of the fat body (87). Studies of Drosophila melanogaster and, more recently, mosquitoes have shown that the fat body specifically expresses aminoacid transporters that function as nutrient sensors (14,61). The level of nutrient reserves accumulated in the fat body modulates several important aspects of the insect's life such as the rate of insect growth, the timing of metamorphosis, and egg development (87). The fat body coordinates insect growth with metamorphosis or reproduction by storing or releasing components central to these events. For example, the synthesis of vitellogenin in the fat body of Aedes aegypti female mosquitoes is NIH Public Access

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Section: Hormonal Regulation Of Fat Body Energy Mobilizationmentioning

confidence: 79%

“…Increases in lipase activity of fat body homogenates after initiation of flight or AKH injection have been observed in several insects (12, 15, 16). AKH induces a fourfold increase in PKA activity of M. sexta fat body in a matter of 2–5 min.…”

Section: Hormonal Regulation Of Fat Body Energy Mobilizationmentioning

confidence: 99%

Insect Fat Body: Energy, Metabolism, and Regulation

Arrese¹,

Soulages²

2010

Annu. Rev. Entomol.

1,925

1,547

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“…Crickets that did not fly during the trial were excluded from the study. In locusts, 5·min of flight activates the mobilization of energy reserves (Auerswald and Gäde, 2006), including the release of lipid 1·h after flight. Auerswald and Gäde (Auerswald and Gäde, 2006) hypothesize that after 5·min of flight, animals are hormonally committed to release lipid.…”

Section: Flying Cricketsmentioning

confidence: 99%

Competition between immune function and lipid transport for the protein apolipophorin III leads to stress-induced immunosuppression in crickets

Adamo

Roberts

Easy

et al. 2008

Journal of Experimental Biology

136

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“…In addition to the effect on the lipid droplets, AKH also induces lipase activation in the cytosol (Auerswald and Gade, 2006; Auerswald et al, 2005; Patel et al, 2006). In Manduca this effect accounts for the remaining 30% of the lipolytic response to AKH (Patel et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

TGL-mediated lipolysis in Manduca sexta fat body: Possible roles for lipoamide-dehydrogenase (LipDH) and high-density lipophorin (HDLp)

Soulages

Joshi

et al. 2014

Insect Biochemistry and Molecular Biology

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Triglyceride-lipase (TGL) is a major fat body lipase in Manduca sexta. The knowledge of how TGL activity is regulated is very limited. A WWE domain, presumably involved in protein-protein interactions, has been previously identified in the N-terminal region of TGL. In this study, we searched for proteins partners that interact with the N-terminal region of TGL. Thirteen proteins were identified by mass spectrometry, and the interaction with four of these proteins was confirmed by immunoblot. The oxidoreductase lipoamide-dehydrogenase (LipDH) and the apolipoprotein components of the lipid transporter, HDLp, were among these proteins. LipDH is the common component of the mitochondrial α-keto acid dehydrogenase complexes whereas HDLp occurs in the hemolymph. However, subcellular fractionation demonstrated that these two proteins are relatively abundant in the soluble fraction of fat body adipocytes. The cofactor lipoate found in typical LipDH substrates was not detected in TGL. However, TGL proved to have critical thiol groups. Additional studies with inhibitors are consistent with the notion that LipDH acting as a diaphorase could preserve the activity of TGL by controlling the redox state of thiol groups. On the other hand, when TG hydrolase activity of TGL was assayed in the presence of HDLp, the production of diacylglycerol (DG) increased. TGL-HDLp interaction could drive the intracellular transport of DG. TGL may be directly involved in the lipoprotein assembly and loading with DG, a process that occurs in the fat body and is essential for insects to mobilize fatty acids. Overall the study suggests that TGL occurs as a multi-protein complex supported by interactions through the WWE domain.

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Endocrine control of TAG lipase in the fat body of the migratory locust, Locusta migratoria

Cited by 35 publications

References 31 publications

Insect Fat Body: Energy, Metabolism, and Regulation

Insect Fat Body: Energy, Metabolism, and Regulation

Competition between immune function and lipid transport for the protein apolipophorin III leads to stress-induced immunosuppression in crickets

TGL-mediated lipolysis in Manduca sexta fat body: Possible roles for lipoamide-dehydrogenase (LipDH) and high-density lipophorin (HDLp)

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