Uptake of storage protein in the rice moth Corcyra cephalonica: identification of storage protein binding proteins in the fat body cell membranes

Kirankumar, N.; Ismail, Sheikh M.; Dutta-Gupta, Aparna

doi:10.1016/s0965-1748(97)00047-7

Cited by 23 publications

(23 citation statements)

References 33 publications

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“…As we have shown earlier, the receptor is present during the last larval instar in an inactive form and is not capable of sequestering hexamerins, i.e. binding its ligand (22,58). Furthermore, it is well documented that the ecdysteroid titer is very low during the last larval instar but increases rapidly (10-fold or more) before pupation (36).…”

Section: E-stimulated Acp Activity Regulation By Hp19mentioning

confidence: 93%

The Insect Hemolymph Protein HP19 Mediates the Nongenomic Effect of Ecdysteroids on Acid Phosphatase Activity

Arif

Vasanthi

Hansen

et al. 2004

Journal of Biological Chemistry

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The activity of acid phosphatase (ACP) in insect fat bodies is stimulated by the steroid hormone 20-hydoxyecdysone (20E) in vivo. However, in fat bodies kept in culture, a factor from the hemolymph is required to enhance the ACP activity. We identified the factor as a protein with a molecular mass of 19 kDa (HP19) from the hemolymph of a lepidopteran insect, the rice moth, Corcyra cephalonica. Western analysis of hemolymph proteins with denaturing and non-denaturing PAGE using antibodies raised against HP19 suggest that this protein exists as a monomer. It is synthesized by the hind gutassociated lobular fat body of the larvae and is released into the hemolymph. The stimulatory effect of HP19 on the ACP activity is developmentally regulated and exhibits its maximal effect shortly before the onset of metamorphosis. We cloned the HP19 cDNA by immunoscreening a hind gut-associated lobular fat body cDNA expression library. Analysis of the amino acid sequence shows that HP19 belongs to the family of glutathione S-transferase (GST) like proteins. However, affinity-purified GST from Corcyra failed to show any mediation effect on 20E-stimulated ACP activity, and HP19 lacks GST enzymatic activity. Notably, HP19 mediates the hormone-stimulated ACP activity in intact fat body tissue and homogenates even in the presence of inhibitors of transcription and translation, suggesting a nongenomic mode of action. In addition, we show that HP19 inhibits the 20E-induced phosphorylation of the hexamerin receptor protein.Insect metamorphosis, the transition from the larval to the adult stage of insects, is controlled by ecdysteroid hormones (1-3). The ecdysteroids, like the steroids in vertebrates, regulate gene transcription by binding to the nuclear receptors, which are ligand-activated transcription factors that convert the hormonal stimulus into a transcription response (4 -7).Metamorphosis involves the breakdown of larval structures and the formation of new tissues (1). As a part of cell remodeling during metamorphosis, acidic autophagic vacuoles accumulate in the cells of the fat body, and the activity of several lysosomal enzymes such as acid phosphatases increase and cause the lysis of larval tissues (8 -11). The fat body fills a large fraction of the insect, and its function has been considered equivalent to the role of the vertebrate liver in the intermediary metabolism (12). It has been demonstrated that the stimulation of the lysosomal activity is governed by ecdysteroids (11, 13-16). There is an indication that in this case the hormone possibly acts on a nongenomic level (17). Although the molecular mechanism of the genomic mode of steroid action is well known, the mechanism of nongenomic steroid action remains unclear to date (18). Earlier studies show that 20E 1 stimulates ACP activity in fat bodies in vivo but not in vitro (19,20). This result suggests that 20E, the active form of ecdysone, requires an additional factor (or factors) to enhance ACP activity. Hence, we have focused on the process of acid phosphatase acti...

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Section: E-stimulated Acp Activity Regulation By Hp19mentioning

confidence: 93%

The Insect Hemolymph Protein HP19 Mediates the Nongenomic Effect of Ecdysteroids on Acid Phosphatase Activity

Arif

Vasanthi

Hansen

et al. 2004

Journal of Biological Chemistry

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“…Immunoblot, ligand and lectin blot analyses of S. litura fat body membrane proteins Fat body membrane proteins of S. litura were prepared by a method described earlier (KiranKumar et al 1997). Membrane proteins were separated by SDS-PAGE and transferred to a nitrocellulose membrane.…”

Section: Northern Blottingmentioning

confidence: 99%

“…Some of the early demonstrations of the pore forming ability of Cry toxin on in vitro cultured fat body tissue were sufficiently convincing only to suggest presence of toxin biding proteins in the fat body of insects (Cheon et al 1997;Cerestiaens et al 2001). In order to investigate if slfbAPN protein had Cry toxin binding ability, ligand blot analysis was carried out by a method described earlier (KiranKumar et al 1997). Ligand blot analysis of the fat body membrane proteins using Cry1C toxin as ligand showed that Cry1 toxin bound to a *120 kDa protein (Fig.…”

Section: S Q a G H P V V N V T I D Y S T E I V T L T Q K R Y Y V N mentioning

confidence: 99%

Characterization of Bacillus thuringiensis Cry toxin binding novel GPI anchored aminopeptidase from fat body of the moth Spodoptera litura

et al. 2007

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Aminopeptidase N (APN) isoforms were identified as candidate receptors for Bacillus thuringiensis Cry toxins from the midgut of several insect species. In this study a partial cDNA encoding aminopeptidase (slfbAPN) was cloned from fat body of the moth Spodoptera litura. In the deduced amino acid sequence the characteristic metallopeptidase sequences, HEXXHX(18)E and GAMENWG were conserved but the sequence showed only 33-39% identity to other insect APNs, which were also reported to be Cry toxin receptors. The presence of a putative GPI anchor signal sequence at the C-terminus indicated that it is a membrane-anchored protein. The slfbAPN expression was restricted to the fat body as suggested by northern blot analysis of different tissues. Biochemical analyses including immunoblotting, ligand blotting and lectin blotting, demonstrated that slfbAPN is a membrane-anchored glycoprotein in the fat body and it binds to Cry toxins.

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“…Hexamerins are taken up by the fat body shortly before pupation and stored in protein granules. The rise in the level of the steroid hormone 20-hydroxyecdysone (20E) at the end of larval life triggers the incorporation of these hexamerins from the haemolymph into the fat body (Burmester and Scheller 1997;Kirankumar et al 1997). Even though the endocytosis of vitellogenins by oocytes is well established, the regulation of hexamerin uptake and their delivery to protein storage granules of the fat body remains elusive, in spite of extensive studies that proposed to investigate whether the uptake process is a 'classical' endocytosis or anything different (Burmester and Scheller 1999).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, GPI-anchored proteins have been reported to be responsible for mediating sequestration or uptake of ligands by phosphorylation (Freedman et al 1998;Solomon et al 1998). Earlier our group reported that tyrosine-kinase-mediated phosphorylation of the~120 kDa putative hexamerin-binding protein (HBP) in the membrane fraction of the fat body (Kirankumar et al 1997;Arif et al 2003) is responsible for the uptake of hexamerins in lepidopteran moth Corcyra cephalonica and this process is regulated by a steroid hormone, 20-hydroxyecdysone (20E).…”

Section: Introductionmentioning

confidence: 99%

Is hexamerin receptor a GPI-anchored protein in Achaea janata (Lepidoptera: Noctuidae)?

2011

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The process of uptake of hexamerins during metamorphosis from insect haemolymph by fat body cells is reminiscent of receptor-mediated endocytosis. Previously, we had identified a hexamerin-binding protein (HBP) and reported for the first time that uptake of hexamerins is dependent on the phosphorylation of HBP partly by a tyrosine kinase, which is, in turn, activated by 20-hydroxyecdysone (20E). However, the exact nature of HBP and the mechanism of interaction are still unknown. Here we report the possibility of HBP being a GPI-anchored protein in the fat body of Achaea janata and its role in the tyrosine-kinase-mediated phosphorylation signalling. Digestion of fat body membrane preparation with bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), and the subsequent recognition by antibodies specific for the cross-reacting determinant (CRD), revealed that HBP is glycosylphosphatidylinositol (GPI)-anchored protein and, further, that the hexamerin binding to HBP was inhibited after digestion. Hexamerin overlay assay (HOA) of co-immunoprecipitated in vitro phosphorylated HBP showed exclusive binding to ~120 kDa protein. Lectin-binding analysis of hexamerins revealed the presence of N-acetylgalactosamine (GalNAc) and N-acetylglucosamine (GluNAc), whereas HBP showed the presence of GalNac alone. Mild chemical deglycosylation studies and binding interaction in the presence of sugars revealed that glycan moieties are possibly not involved in the interaction between HBP and hexamerins. Taken together, these results suggest that HBP may be a GPI-anchored protein, and interaction and activation of HBP is through lipid-linked non-receptor src tyrosine kinases. However, additional studies are needed to prove that HBP is a GPI-anchored protein.

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Uptake of storage protein in the rice moth Corcyra cephalonica: identification of storage protein binding proteins in the fat body cell membranes

Cited by 23 publications

References 33 publications

The Insect Hemolymph Protein HP19 Mediates the Nongenomic Effect of Ecdysteroids on Acid Phosphatase Activity

The Insect Hemolymph Protein HP19 Mediates the Nongenomic Effect of Ecdysteroids on Acid Phosphatase Activity

Characterization of Bacillus thuringiensis Cry toxin binding novel GPI anchored aminopeptidase from fat body of the moth Spodoptera litura

Is hexamerin receptor a GPI-anchored protein in Achaea janata (Lepidoptera: Noctuidae)?

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