UV irradiation and desiccation modulate the three-dimensional extracellular matrix of Nostoc commune (Cyanobacteria).
Cyanobacterium Nostoc commune can tolerate the simultaneous stresses of desiccation, UV irradiation, and oxidation. Acidic WspA, of approximately 33.6 kDa, is secreted to the three-dimensional extracellular matrix and accounts for greater than 70% of the total soluble protein. The wspA gene of N. commune strain DRH1 was cloned and found in a single genomic copy, in a monocistronic operon. Transcription of wspA and sodF (superoxide dismutase), and synthesis and secretion of WspA, were induced upon desiccation or UV-A/B irradiation of cells. Recombinant WspA binds the UV-A/B absorbing pigment scytonemin through non-covalent interactions. WspA peptide polymorphism, and heterogeneity of multiple wspA sequences within cells of a single colony, account for distinct WspA isoforms. WspA has no similarity to entries in the sequence databases and wspA, a possible xenolog, is restricted to a subset of strains in the "form species" N. commune characterized through group I intron phylogeny. We hypothesize that WspA plays a central role in the global stress response of N. commune through modulation of the structure and function of the three-dimensional extracellular matrix, particularly the transport, distribution, and/or macromolecular architecture of mycosporine and scytonemin UV-A/B absorbing pigment complexes.
Wright
Deborah J
DJ
Virginia Tech Center for Genomics, Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, USA.
Smith
Sue C
SC
Joardar
Vinita
V
Scherer
Siegfried
S
Jervis
Jody
J
Warren
Andrew
A
Helm
Richard F
RF
Potts
Malcolm
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D002853:Chromatography, Liquid; D005109:Extracellular Matrix / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism; D007211:Indoles / Q000737:chemistry / Q000378:metabolism; D007525:Isoelectric Focusing; D013058:Mass Spectrometry; D008956:Models, Chemical; D008957:Models, Genetic; D008969:Molecular Sequence Data; D050501:Nostoc commune / Q000378:metabolism*; D016366:Open Reading Frames; D010100:Oxygen / Q000737:chemistry; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D010636:Phenols / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D011110:Polymorphism, Genetic; D011134:Polysaccharides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D013482:Superoxide Dismutase / Q000378:metabolism; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
D006360:Heat-Shock Proteins; D007211:Indoles; D010455:Peptides; D010636:Phenols; D011134:Polysaccharides; D011994:Recombinant Proteins; C083368:scytonemin; D010397:Penicillanic Acid; D013482:Superoxide Dismutase; C004408:aminopenicillanic acid; D010100:Oxygen