Leishmania donovani heat shock protein 100. Characterization and function in amastigote stage differentiation.
We report the cloning and molecular analysis of the Leishmania donovani clpB gene. The protein-coding region is highly conserved compared with its L. major homologue, while 5'- and 3'-flanking DNA sequences display considerable divergence. The encoded mRNA has an unusually long 5'-leader sequence typical for RNAs, which are translated preferentially under heat stress. The gene product, a 100-kDa heat shock protein, Hsp100, becomes abundant only during sustained heat stress, but not under common chemical stresses. Hsp100 associates into trimeric complexes and is found mostly in a cytoplasmic, possibly membrane-associated, localization as determined by immune electron microscopy. Hsp100 shows immediate early expression kinetics during axenic amastigote development. In its absence, expression of at least one amastigote stage-specific protein family is impaired.
Krobitsch
S
S
Leishmaniasis Unit, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany.
Brandau
S
S
Hoyer
C
C
Schmetz
C
C
Hübel
A
A
Clos
J
J
D000818:Animals; D001483:Base Sequence; D002451:Cell Compartmentation; D002454:Cell Differentiation; D003001:Cloning, Molecular; D017124:Conserved Sequence; D049071:Endopeptidase Clp; D005786:Gene Expression Regulation; D017125:Genes, Protozoan; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D018869:Heat-Shock Response; D007893:Leishmania donovani / Q000166:cytology / Q000235:genetics*; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D006360:Heat-Shock Proteins; D015800:Protozoan Proteins; D049071:Endopeptidase Clp; C095049:ClpB protein, Leishmania