title: Hlcyst-1 and Hlcyst-2 are potential inhibitors of HlCPL-A in the midgut of the ixodid tick Haemaphysalis longicornis.
abstract: Although the actions of cysteine proteases are controlled in part by endogenous tight-binding cysteine protease inhibitors from the cystatin superfamily, regulatory mechanisms used by ticks to control protease activities are unknown. We report here the interaction of 2 endogenous midgut cysteine protease inhibitors, Hlcyst-1 and Hlcyst-2, with an endogenous midgut cysteine protease, HlCPL-A in Haemaphysalis longicornis. In vitro inhibition assays demonstrated that the hydrolytic activity of HlCPL-A was inhibited by Hlcyst-1 and Hlcyst-2 in dose dependent manner. Immunofluorescent studies revealed that Hlcyst-1 and Hlcyst-2 are co-localized with HlCPL-A in the epithelial cells of the midgut. The hemoglobin degradation activity of HlCPL-A was dose-dependently inhibited by Hlcyst-1 and Hlcyst-2. These results strongly indicate that, Hlcyst-1 and Hlcyst-2 are possible inhibitor of HlCPL-A and play a key role in regulatory mechanisms of hemoglobin degradation process in ticks.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305-8572.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Yamaji
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Tsuji
authors.forename: Takeharu
authors.initials: T
authors.lastname: Miyoshi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hatta
authors.forename: M Abdul
authors.initials: MA
authors.lastname: Alim
authors.lastname: Anisuzzaman
authors.forename: Shiro
authors.initials: S
authors.lastname: Kushibiki
authors.forename: Kozo
authors.initials: K
authors.lastname: Fujisaki
mesh_terms: D000595:Amino Acid Sequence; D000821:Animal Feed; D000818:Animals; D001769:Blood; D015891:Cystatins / Q000737:chemistry / Q000494:pharmacology*; D057056:Cysteine Proteases / Q000378:metabolism*; D004064:Digestive System / Q000187:drug effects* / Q000378:metabolism; D026863:Ixodidae / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D007700:Kinetics; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012469:Salivary Glands / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D015891:Cystatins; D009842:Oligopeptides; D011480:Protease Inhibitors; D057056:Cysteine Proteases