Identification and characterization of cytosolic Hansenula polymorpha proteins belonging to the Hsp70 protein family.
We have isolated two members of the Hsp70 protein family from the yeast Hansenula polymorpha using affinity chromatography. Both proteins were located in the cytoplasm. One of these, designated Hsp72, was inducible in nature (e.g. by heat shock). The second protein (designated Hsc74) was constitutively present. Peptides derived from both Hsp72 and Hsc74 showed sequence homology to the cytosolic Saccharomyces cerevisiae Hsp70s, Ssa1p and Ssa2p. The gene encoding Hsp72 (designated HSA1) was cloned, sequenced and used to construct HSA1 disruption and HSA1 overexpression strains. Comparison of the stress tolerances of these strains with those of wild-type H. polymorpha revealed that HSA1 overexpression negatively affected the tolerance of the cells to killing effects of temperature or ethanol, but enhanced the tolerance to copper and cadmium. The tolerance for other chemicals (arsenite, arsenate, H2O2) or to high osmolarity was unaffected by either deletion or overexpression of HSA1.
Titorenko
V I
VI
Department of Microbiology, Groningen Biomolecular Sciences, Haren, The Netherlands.
Evers
M E
ME
Diesel
A
A
Samyn
B
B
Van Beeumen
J
J
Roggenkamp
R
R
Kiel
J A
JA
van der Klei
I J
IJ
Veenhuis
M
M
D002104:Cadmium / Q000494:pharmacology; D002451:Cell Compartmentation; D003001:Cloning, Molecular; D003300:Copper / Q000494:pharmacology; D003600:Cytosol / Q000737:chemistry*; D004351:Drug Resistance; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification*; D015870:Gene Expression; D005800:Genes, Fungal; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000302:isolation & purification*; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000235:genetics / Q000302:isolation & purification; D018869:Heat-Shock Response; D008830:Microbodies / Q000502:physiology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010843:Pichia / Q000737:chemistry* / Q000235:genetics; D017422:Sequence Analysis, DNA
D005656:Fungal Proteins; D018840:HSP70 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D010446:Peptide Fragments; D002104:Cadmium; D003300:Copper