A tyrosine-rich cell surface protein in the diatom Amphora coffeaeformis identified through transcriptome analysis and genetic transformation.
Diatoms are single-celled eukaryotic microalgae that are ubiquitously found in almost all aquatic ecosystems, and are characterized by their intricately structured SiO2 (silica)-based cell walls. Diatoms with a benthic life style are capable of attaching to any natural or man-made submerged surface, thus contributing substantially to both microbial biofilm communities and economic losses through biofouling. Surface attachment of diatoms is mediated by a carbohydrate- and protein- based glue, yet no protein involved in diatom underwater adhesion has been identified so far. In the present work, we have generated a normalized transcriptome database from the model adhesion diatom Amphora coffeaeformis. Using an unconventional bioinformatics analysis we have identified five proteins that exhibit unique amino acid sequences resembling the amino acid composition of the tyrosine-rich adhesion proteins from mussel footpads. Establishing the first method for the molecular genetic transformation of A. coffeaeformis has enabled investigations into the function of one of these proteins, AC3362, through expression as YFP fusion protein. Biochemical analysis and imaging by fluorescence microscopy revealed that AC3362 is not involved in adhesion, but rather plays a role in biosynthesis and/or structural stability of the cell wall. The methods established in the present study have paved the way for further molecular studies on the mechanisms of underwater adhesion and biological silica formation in the diatom A. coffeaeformis.
B CUBE Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany.
Matthias T
MT
Buhmann
B CUBE Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany.
Nicole
N
Poulsen
B CUBE Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany.
Jennifer
J
Klemm
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
Matthew R
MR
Kennedy
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
C David
CD
Sherrill
B CUBE Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany; Department of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden, Germany.
Nils
N
Kröger
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D017377:Diatoms / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D059467:Transcriptome; D014443:Tyrosine / Q000737:chemistry
D008565:Membrane Proteins; D014443:Tyrosine