A Kunitz type protease inhibitor related protein is synthesized in Drosophila prepupal salivary glands and released into the moulting fluid during pupation.
From the Drosophila virilis late puff region 31C, we microcloned two neighbouring genes, Kil-1 and Kil-2, that encode putative Kunitz serine protease inhibitor like proteins. The Kil-1 gene is expressed exclusively in prepupal salivary glands. Using a size mutant of the KIL-1 protein and MALDI-TOF analysis, we demonstrate that during pupation this protein is released from the prepupal salivary glands into the pupation fluid covering the surface of the pupa. 3-D-structure predictions are consistent with the known crystal structure of the human Kunitz type protease inhibitor 2KNT. This is the first experimental proof for the extracorporal presence of a distinct Drosophila prepupal salivary gland protein. Possible functions of KIL-1 in the context of the control of proteolytic activities in the pupation fluid are discussed.
Kress
Horst
H
Institut für Biologie-Genetik, Freie Universität Berlin, Arnimallee 7, D-14195, Germany. kress@zedat.fu-berlin.de
Jarrin
Andres
A
Thüroff
Eduardo
E
Saunders
Robert
R
Weise
Chris
C
Schmidt am Busch
Marcel
M
Knapp
Ernst-W
EW
Wedde
Marianne
M
Vilcinskas
Andreas
A
D000595:Amino Acid Sequence; D000818:Animals; D007611:Aprotinin / Q000737:chemistry*; D001483:Base Sequence; D003001:Cloning, Molecular; D004330:Drosophila / Q000235:genetics* / Q000254:growth & development; D010450:Endopeptidases / Q000378:metabolism; D019143:Evolution, Molecular; D017344:Genes, Insect / Q000235:genetics; D007814:Larva / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020161:Physical Chromosome Mapping; D011679:Pupa / Q000235:genetics / Q000378:metabolism; D012469:Salivary Glands / Q000254:growth & development* / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D012471:Salivary Proteins and Peptides; D014361:Trypsin Inhibitors; D007611:Aprotinin; D010450:Endopeptidases