Disease relevance of Lsp2

• In this study aimed at developing a vaccine for humans, West Nile virus (WNV) envelope protein (E) and non-structural protein 1 (NS1) were produced in the Drosophila S2 cell expression system [1].

High impact information on Lsp2

• The structural gene for larval serum protein 2 (LSP 2) lies at 68E3 or 4, and that for salivary glue secretion protein 3 between 68A8 and 68C11, coincident with a major intermoult puff active in the salivary gland at the time of glue synthesis [2].
• The LSP-2 gene and a 5' flanking sequence are independently expressed in Drosophila melanogaster [3].
• During normal larval development, the LSP-2 gene is expressed before the P1 gene, and this order is also observed in the cultured fat bodies [4].
• Furthermore, although expression of the caspase inhibitors p35 or Drosophila inhibitor of apoptosis protein 1 blocked starvation-induced death, it did not affect normal nurse cell death or overall oogenesis in well-fed females [5].
• Sequence analysis of the 5'-flanking region of the gene revealed a high GC content, six CCGCCC Sp-1-binding motifs, CREB, LBP-1 (leader-binding protein 1), and TGGCA-binding consensus sites [6].

Biological context of Lsp2

• The amino acid sequence of Lsp-1 beta is 65.8% identical to that of calliphorin, the major hexamerin of the blowfly, Calliphora vicina, and only 35.2% identical to Drosophila Lsp-2 [7].
• We detected in the Lsp-2 gene a 2052-bp antisense ORF that probably does not code for any protein [8].
• To understand the structural and functional differences between these two storage hexamers, the nucleotide sequence of the coding region of the Lsp-1 beta gene was determined for comparison with LSP-2 and a number of other arthropod hexamerins [7].
• Our results together with those of Singh and Coulthart [(1982). Genetics 102:437] indicate that D. melanogaster populations in north temperate climates maintain considerable genetic heterogeneity for the larval hemolymph proteins [9].
• A single functional ecdysone response element (EcRE) was localized at position -75 relative to the Lsp-2 transcription initiation site [10].

Anatomical context of Lsp2

• The larval serum proteins, LSP1 and LSP2, of Drosophila melanogaster are synthesized by the fat body during the third instar [11].
• The mammalian ARF-like protein 1 (Arl1) is associated with the Golgi complex [12].
• Drosophila hemolymph proteins: purification, characterization, and genetic mapping of larval serum protein 2 in D. melanogaster [13].
• Here we report that Lsp-2 transcription in adult flies produces a unique mRNA localized in the adult adipose tissue of the head in both sexes [14].
• Ran requires RanGTPase-activating protein-1 (RanGAP1) on the cytoplasmic side of nuclear pore complexes to convert Ran-GTP to Ran-GDP [15].

Associations of Lsp2 with chemical compounds

• Transcription of Lsp-2 is controlled by 20-hydroxyecdysone [8].
• This greater similarity to calliphorin is also reflected in high aromatic amino acid and methionine contents, in contrast to LSP-2 which is enriched to a lesser extent only in aromatic amino acids [7].
• Osmotic concentration in the larval hemolymph is correlated with leucine aminopeptidase activity, but changes in hemolymph osmotic concentration in response to environmental osmotic stress depend on the osmotic effector in the environment [16].
• The endogenous concentrations of the critical, dietary-derived delta 5,7-sterols ergosterol and 7-dehydrocholesterol (7dC) remained 10 to 20-fold higher in the Manduca pupal and adult nervous tissues than was found in the larval hemolymph at the cessation of feeding [17].
• An analysis of the released oligosaccharides from a membrane glycoprotein preparation of third instar larvae (3rdIL), and purified larval serum protein 2 (LSP2) from Drosophila melanogaster was performed [18].

Physical interactions of Lsp2

• Proline-rich synapse-associated protein-1/cortactin binding protein 1 (ProSAP1/CortBP1) is a PDZ-domain protein highly enriched in the postsynaptic density [19].

Other interactions of Lsp2

• Proteins 9, 10, 11, and 15 correspond to the LSP-1 gamma, beta, and alpha triplet and LSP-2 polypeptide in D. melanogaster [9].
• Characterization of an EcR/USP heterodimer target site that mediates ecdysone responsiveness of the Drosophila Lsp-2 gene [10].
• Induction was demonstrated by increased amounts of LSP-2 and P1 transcripts in the ecdysterone-supplemented fat bodies [4].
• The Pl gene, together with the LSP-1 alpha, -1 beta, and -1 gamma, LSP-2, and P6 genes, is expressed exclusively in the larval fat body of D. melanogaster during the third instar [20].
• After knockdown of fon by RNAi, bead aggregation activity of larval hemolymph is strongly reduced, and wound closure is affected. fon is thus the second Drosophila gene after hemolectin (hml), for which a knockdown causes a clotting phenotype [21].

Analytical, diagnostic and therapeutic context of Lsp2

• Western blot analysis using an LSP-2 antiserum reveals notable differences in the molecular weight of the larval and adult polypeptides [22].
• Larval hemolymph tyrosinase activity in Drosophila melanogaster was detected with high performance liquid chromatography with electrochemical detection [23].
• [7P]m type of D. melanogaster, characterized with an excess of C25 compounds, presents a higher resistance against desiccation than [7T]m type, where C23 compounds are more abundant [24].
• Rocker immunoelectrophoresis was used to estimate aldehyde oxidase cross-reacting material (AO-CRM) in larval hemolymph and adult fly extracts in mutants with reduced AO enzymatic activity [25].

References