Hydrophilins in the filamentous fungus Neosartorya fischeri (Aspergillus fischeri) have protective activity against several types of microbial water stress.
Hydrophilins are proteins that occur in all domains of life and protect cells and organisms against drought and other stresses. They include most of the late embryogenesis abundant (LEA) proteins and the heat shock protein (HSP) Hsp12. Here, the role of a predicted LEA-like protein (LeamA) and two Hsp12 proteins (Hsp12A and Hsp12B) of Neosartorya fischeri was studied. This filamentous fungus forms ascospores that belong to the most stress-resistant eukaryotic cells described to date. Heterologous expression of LeamA, Hsp12A and Hsp12B resulted in increased tolerance against salt and osmotic stress in Escherichia coli. These proteins were also shown to protect lactate dehydrogenase against dry heat and freeze-thaw cycles in vitro. Deletion of leamA caused diminished viability of sexual ascospores after drought and heat. This is the first report on functionality of Hsp12 and putative LeamA proteins derived from filamentous fungi, and their possible role in N. fischeri ascospore resistance against desiccation, high temperature and osmotic stress is discussed.
CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, Utrecht, 3584 CT, The Netherlands.
M R
MR
van Leeuwen
CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, Utrecht, 3584 CT, The Netherlands.
T T
TT
Wyatt
CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, Utrecht, 3584 CT, The Netherlands.
T M
TM
van Doorn
Microbiology, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
L G
LG
Lugones
Microbiology, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
H A B
HA
Wösten
CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, Utrecht, 3584 CT, The Netherlands.
J
J
Dijksterhuis
D003001:Cloning, Molecular; D003681:Dehydration; D055864:Droughts; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015870:Gene Expression; D006358:Hot Temperature; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D050296:Microbial Viability / Q000187:drug effects; D055326:Neosartorya / Q000187:drug effects / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D009997:Osmotic Pressure; D013312:Stress, Physiological
D005656:Fungal Proteins; D007770:L-Lactate Dehydrogenase