title: The Involvement of hybrid cluster protein 4, HCP4, in Anaerobic Metabolism in Chlamydomonas reinhardtii.
abstract: The unicellular green algae Chlamydomonas reinhardtii has long been studied for its unique fermentation pathways and has been evaluated as a candidate organism for biofuel production. Fermentation in C. reinhardtii is facilitated by a network of three predominant pathways producing four major byproducts: formate, ethanol, acetate and hydrogen. Previous microarray studies identified many genes as being highly up-regulated during anaerobiosis. For example, hybrid cluster protein 4 (HCP4) was found to be one of the most highly up-regulated genes under anoxic conditions. Hybrid cluster proteins have long been studied for their unique spectroscopic properties, yet their biological functions remain largely unclear. To probe its role during anaerobiosis, HCP4 was silenced using artificial microRNAs (ami-hcp4) followed by extensive phenotypic analyses of cells grown under anoxic conditions. Both the expression of key fermentative enzymes and their respective metabolites were significantly altered in ami-hcp4, with nitrogen uptake from the media also being significantly different than wild-type cells. The results strongly suggest a role for HCP4 in regulating key fermentative and nitrogen utilization pathways.
authors.affiliation: Integrated Biosciences Graduate Program, University of Minnesota, Duluth, MN, 55812, United States of America.
authors.forename: Adam C
authors.initials: AC
authors.lastname: Olson
authors.affiliation: Department of Plant Biology, University of Minnesota, Saint Paul, MN, 55108, United States of America.
authors.forename: Clay J
authors.initials: CJ
authors.lastname: Carter
mesh_terms: D000085:Acetates / Q000378:metabolism; D020418:Algal Proteins / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D064751:Ammonium Compounds / Q000378:metabolism; D000693:Anaerobiosis; D016825:Chlamydomonas reinhardtii / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation / Q000235:genetics / Q000502:physiology*; D005561:Formates / Q000378:metabolism; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques; D006859:Hydrogen / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D000085:Acetates; D020418:Algal Proteins; D064751:Ammonium Compounds; D005561:Formates; D009566:Nitrates; D000431:Ethanol; D006859:Hydrogen; D009584:Nitrogen