A gene family of cathepsin L-like proteases of filarial nematodes are associated with larval molting and cuticle and eggshell remodeling.
Cysteine proteinases are involved in a variety of important biological processes and have been implicated in molting and tissue remodeling in free living and parasitic nematodes. We show that in the lymphatic filarial nematode Brugia pahangi molting of third-stage larvae (L3) to fourth-stage larvae is dependent on the activity of a cathepsin L-like cysteine protease (CPL), which can be detected in the excretory/secretory (ES) products of molting L3. Directed cloning of a cysteine protease gene in B. pahangi and analysis of the expressed sequence tag (EST) and genomic sequences of the closely related human lymphatic filarial nematode Brugia malayi have identified a family of CPLs. One group of these enzymes, Bm-cpl-1, -4, -5 and Bp-cpl-4, is highly expressed in the B. malayi and B. pahangi infective L3 larvae. Immunolocalization indicates that the corresponding enzymes are synthesized and stored in granules of the glandular esophagus of L3 and released during the molting process. Functional analysis of these genes in Brugia and closely related CPL genes identified in the filarial nematode Onchocerca volvulus and the free living model nematode Caenorhabditis elegans indicate that these genes are also involved in cuticle and eggshell remodeling.
Department of Biological Sciences, Imperial College of Science and Technology, London SW7 2AY, UK.
David B
DB
Guiliano
Xiqiang
X
Hong
James H
JH
McKerrow
Mark L
ML
Blaxter
Yelena
Y
Oksov
Jing
J
Liu
Elodie
E
Ghedin
Sara
S
Lustigman
D000818:Animals; D001483:Base Sequence; D017178:Brugia malayi / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D017179:Brugia pahangi / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D056668:Cathepsin L; D002403:Cathepsins / Q000235:genetics*; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000235:genetics; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D018509:DNA, Helminth / Q000235:genetics; D004528:Egg Shell / Q000254:growth & development; D020224:Expressed Sequence Tags; D017238:Genes, Helminth; D007814:Larva / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D018978:Molting / Q000187:drug effects / Q000502:physiology; D005810:Multigene Family; D010802:Phylogeny; D013045:Species Specificity
D015853:Cysteine Proteinase Inhibitors; D018509:DNA, Helminth; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L