Drosophila Chitinase 2 is expressed in chitin producing organs for cuticle formation.
The architecture of the outer body wall cuticle is fundamental to protect arthropods against invading pathogens and numerous other harmful stresses. Such robust cuticles are formed by parallel running chitin microfibrils. Molting and also local wounding leads to dynamic assembly and disassembly of the chitin-matrix throughout development. However, the underlying molecular mechanisms that organize proper chitin-matrix formation are poorly known. Recently we identified a key region for cuticle thickening at the apical cell surface, the cuticle assembly zone, where Obstructor-A (Obst-A) coordinates the formation of the chitin-matrix. Obst-A binds chitin and the deacetylase Serpentine (Serp) in a core complex, which is required for chitin-matrix maturation and preservation. Here we present evidence that Chitinase 2 (Cht2) could be essential for this molecular machinery. We show that Cht2 is expressed in the chitin-matrix of epidermis, trachea, and the digestive system. There, Cht2 is enriched at the apical cell surface and the dense chitin-matrix. We further show that in Cht2 knockdown larvae the assembly zone is rudimentary, preventing normal cuticle formation and pore canal organization. As sequence similarities of Cht2 and the core complex proteins indicate evolutionarily conserved molecular mechanisms, our findings suggest that Cht2 is involved in chitin formation also in other insects.
Institute for Biology and Sächsischer Inkubator für klinische Translation (TRM/SIKT), University of Leipzig, 04103 Leipzig, Germany; Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany.
Yanina-Yasmin
YY
Pesch
Max Planck Institute for Biophysical Chemistry, Electron Microscopy Group, 37077 Göttingen, Germany.
Dietmar
D
Riedel
Institute for Biology and Sächsischer Inkubator für klinische Translation (TRM/SIKT), University of Leipzig, 04103 Leipzig, Germany; Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany. Electronic address: matthias.behr@uni-leipzig.de.
Matthias
M
Behr
D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002686:Chitin / Q000096:biosynthesis*; D002688:Chitinases / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000254:growth & development; D004817:Epidermis / Q000196:embryology / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000196:embryology / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000378:metabolism*; D007814:Larva / Q000254:growth & development*; D008856:Microscopy, Fluorescence; D018978:Molting; D000072417:Protein Domains; D034622:RNA Interference; D012469:Salivary Glands / Q000196:embryology / Q000378:metabolism; D014132:Trachea / Q000196:embryology / Q000378:metabolism
D002352:Carrier Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; C574473:Obst-A protein, Drosophila; C047663:cuticle proteins, insects; D002686:Chitin; D002688:Chitinases; C000615621:chitinase 2, Drosophila; D000581:Amidohydrolases; C509513:serp protein, Drosophila
Arthropod; Epidermis; Epithelia; Gut; Salivary gland; Tracheal system