ABSTRACT
The late endosomal marker Rab7 has been long believed to be absent from the phagosome containing Mycobacterium tuberculosis (M.tb) in macrophage, but the detail kinetics remains elusive. Here, we found that Rab7 is transiently recruited to and subsequently released from M.tb phagosomes. For further understanding of the effect of Rab7 dissociation from the phagosome, we examined the localization of lysosomal markers on the phagosome in the macrophage expressing a dominant-negative Rab7. The localization of lysosomal associated membrane protein-2 (LAMP-2) on the phagosome was Rab7-independent, while that of cathepsin D was Rab7-dependent. These results agree with the localization of each lysosomal marker on M.tb phagosome at 6h postinfection-i.e., LAMP-2, but not cathepsin D localized on the majority of M.tb phagosomes. These results suggest that the dissociation of Rab7 from M.tb phagosome is the important process in inhibition of phagolysosome biogenesis.
Subject(s)
Macrophages/microbiology , Mycobacterium tuberculosis , Phagosomes/enzymology , rab GTP-Binding Proteins/metabolism , Animals , Cell Line , Humans , Macrophages/ultrastructure , Mice , rab7 GTP-Binding ProteinsABSTRACT
A contig-oriented database for annotation of the rice genome has been constructed to facilitate map-based rice genomics. The Rice Annotation Database has the following functional features: (i) extensive effort of manual annotations of P1-derived artificial chromosome/bacterial artificial chromosome clones can be merged at chromosome and contig-level; (ii) concise visualization of the annotation information such as the predicted genes, results of various prediction programs (RiceHMM, Genscan, Genscan+, Fgenesh, GeneMark, etc.), homology to expressed sequence tag, full-length cDNA and protein; (iii) user-friendly clone / gene query system; (iv) download functions for nucleotide, amino acid and coding sequences; (v) analysis of various features of the genome (GC-content, average value, etc.); and (vi) genome-wide homology search (BLAST) of contig- and chromosome-level genome sequence to allow comparative analysis with the genome sequence of other organisms. As of October 2004, the database contains a total of 215 Mb sequence with relevant annotation results including 30 000 manually curated genes. The database can provide the latest information on manual annotation as well as a comprehensive structural analysis of various features of the rice genome. The database can be accessed at http://rad.dna.affrc.go.jp/.
