Deletion of the gene for the membrane-bound acid phosphatase of Leishmaniamexicana

The membrane-bound acid phosphatase of Leishmania mexicana (LmxMBAP) has be en shown to be a heterogeneously N-glycosylated type I transmembrane protei n, which is localized predominantly in vesicular structures close to the fl agellar pocket in promastigotes and amastigotes. Its expression in both lif e stages prompted us td analyse its function by performing deletion analysi s. Both alleles of the single copy gene were sequentially replaced by resis tance marker genes and the resulting deletion mutant was tested for its pot ential to infect Balb/c mice and peritoneal macrophages. There was no obvio us difference detectable between the mutant and the wild-type. Therefore, w e conclude that LmxMBAP is neither involved in the infection process nor re quired for amastigote survival in the infected host cell. LmxMBAP null muta nt promastigotes were used to establish a system for homogeneous overexpres sion of LmxMBAP which will be useful to investigate protein sorting in L. m exicana. (C) 2000 Elsevier Science B.V. All rights reserved.