Open AccessEcotin‐like serine peptidase inhibitor ISP1 of Leishmania major plays a role in flagellar pocket dynamics and promastigote differentiation
Author(s) -
Morrison Lesley S.,
Goundry Amy,
Faria Marilia S.,
Tetley Laurence,
Eschenlauer Sylvain C.,
Westrop Gareth D.,
Dostalova Anna,
Volf Petr,
Coombs Graham H.,
Lima Ana Paula C. A.,
Mottram Jeremy C.
Publication year - 2012
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/j.1462-5822.2012.01798.x
Subject(s) - biology , flagellum , leishmania , microbiology and biotechnology , mutant , leishmania major , elastase , serine , motility , gene , biochemistry , enzyme , parasite hosting , phosphorylation , world wide web , computer science
Summary Leishmania ISPs are ecotin‐like natural peptide inhibitors of trypsin‐family serine peptidases, enzymes that are absent from the Leishmania genome. This led to the proposal that ISPs inhibit host serine peptidases and we have recently shown that ISP2 inhibits neutrophil elastase, thereby enhancing parasite survival in murine macrophages. In this study we show that ISP1 has less serine peptidase inhibitory activity than ISP2, and in promastigotes both are generally located in the cytosol and along the flagellum. However, in haptomonad promastigotes there is a prominent accumulation of ISP1 and ISP2 in the hemidesmosome and for ISP2 on the cell surface. An L. major mutant deficient in all three ISP genes (Δ isp1/2/3 ) was generated and compared with Δ isp2/3 mutants to elucidate the physiological role of ISP1. In in vitro cultures, the Δ isp1/2/3 mutant contained more haptomonad, nectomonad and leptomonad promastigotes with elongated flagella and reduced motility compared with Δ isp2/3 populations, moreover it was characterized by very high levels of release of exosome‐like vesicles from the flagellar pocket. These data suggest that ISP1 has a primary role in flagellar homeostasis, disruption of which affects differentiation and flagellar pocket dynamics.