Hydrophobins DGH1, DGH2, and DGH3 in the lichen-forming basidiomycete Dictyonema glabratum.
Dictyonema glabratum is a lichen-forming basidiomycete whose symbiotic phenotype shares similarities to both lichens and its non-lichen-forming relatives. In the photobiont layer of D. glabratum intercellular gas-filled spaces are present even when the lichen is water-saturated. The walls of hyphae lining air cavities are covered by a hydrophobic, rodlet-patterned layer, assumed to be formed by hydrophobins. Hot SDS-insoluble, but trifluoroacetic acid-soluble lichen cell wall extracts contained seven proteins. The N-terminal sequence of the most abundant 14-kDa protein was used to carry out cDNA cloning by RT-PCR. The deduced amino acid sequence of the amplified fragment encoded a class I hydrophobin, called DGH1. The cDNA sequence encoding the signal peptide was cloned by RACE-PCR, which also coamplified cDNA fragments encoding two additional class I hydrophobins, DGH2 and DGH3. The three proteins share 54 to 66% amino acid identity. The D. glabratum hydrophobin extract containing either all proteins or primarily DGH1 self-assembled and formed a rodlet mosaic similar to the one observed in situ. Concentration of the protein extract was shown to influence the length of the self-assembled rodlets.
Trembley
Marcella L
ML
Institute of Plant Biology, University of Zurich, Zurich, CH-8008, Switzerland.
Ringli
Christoph
C
Honegger
Rosmarie
R
D000595:Amino Acid Sequence; D001487:Basidiomycota / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology; D057927:Hydrophobic and Hydrophilic Interactions; D008011:Lichens / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
D005656:Fungal Proteins