graal: a Drosophila gene coding for several mosaic serine proteases

• Published in: Insect biochemistry and molecular biology Vol. 34; no. 10; pp. 1025 - 1035
• Main Authors: Munier, Anne Isabelle, Medzhitov, Ruslan, Janeway, Charles A., Doucet, Daniel, Capovilla, Maria, Lagueux, Marie
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2004; Elsevier
• Subjects: alternative splicing; Amino Acid Sequence; amino acid sequences; Animals; Animals, Genetically Modified; Base Sequence; Biochemistry, Molecular Biology; chemistry; Chitin-binding domain; Cloning, Molecular; DNA, Complementary; DNA, Complementary - genetics; Drosophila; Drosophila - enzymology; Drosophila - genetics; Drosophila - immunology; Drosophila immune response; enzymology; gene induction; Genes, Insect; genetics; graal gene; immune response; Immunology; Innate immunity; insect immunity; Isoenzymes; Isoenzymes - chemistry; Isoenzymes - genetics; Isoenzymes - physiology; Life Sciences; metabolism; Molecular biology; Molecular Sequence Data; nucleotide sequences; physiology; protein domains; Protein Structure, Tertiary; retrotransposons; RNA, Messenger; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Homology, Amino Acid; Serine Endopeptidases; Serine Endopeptidases - chemistry; Serine Endopeptidases - genetics; Serine Endopeptidases - physiology; Serine protease; serine proteinases; SRCR domain; structural genes; transcription (genetics); PGRP, peptidoglycan recognition protein; SRCR domain; SRCR, scavenger receptor cysteine-rich; Serine protease; CBD, chitin-binding domain; MARCO, macrophage receptor with collagenous structure; HRG, His-rich glycoprotein; Chitin-binding domain; Drosophila immune response; SR-A, scavenger receptor type A; LDLR-CR, low density lipoprotein receptor cysteine-rich; BDGP, Berkeley Drosophila genome project
• ISSN: 0965-1748; 1879-0240
• DOI: 10.1016/j.ibmb.2003.09.009

Serine proteases play vital roles in several biological processes such as development and immunity. We have characterized Graal, a large multi-domain serine protease from Drosophila. Graal is spliced in at least three transcripts that are present throughout development. The domains found in Graal proteins are: chitin-binding domains (CBD), scavenger receptor cysteine-rich (SRCR) domains, low density lipoprotein receptor cysteine-rich (LDLR-CR) domains, histidine and proline-rich domains, a NGGYQPP-repeat domain and a serine protease domain. The last 2370 nucleotides of these RNAs are identical and encode a His-rich domain, two SRCR domains, two LDLR-CR domains and a protease domain. The transcription of graal is upregulated after fungal or bacterial infection. Analysis of the Iso1 ( y;cn,sp,bw) strain shows that graal transcription is impaired in this fly line due to the insertion of a retrotransposon in the sixth exon. However, no phenotype could be observed consecutive to the absence of graal full length transcripts, particularly in the context of an immune challenge.