title: Expression of the urease gene of Agaricus bisporus: a tool for studying fruit body formation and post-harvest development.
abstract: Fruit body initials of Agaricus bisporus contain high levels of urea, which decrease in the following developmental stages until stage 4 (harvest) when urea levels increase again. At storage, the high urea content may affect the quality of the mushroom, i.e. by the formation of ammonia from urea through the action of urease (EC 3.5.1.5). Despite the abundance of urea in the edible mushroom A. bisporus, little is known about its physiological role. The urease gene of A. bisporus and its promoter region were identified and cloned. The coding part of the genomic DNA was interrupted by nine introns as confirmed by cDNA analysis. The first full homobasidiomycete urease protein sequence obtained comprised 838 amino acids (molecular mass 90,694 Da, pI 5.8). An alignment with fungal, plant and bacterial ureases revealed a high conservation. The expression of the urease gene, measured by Northern analyses, was studied both during normal development of fruit bodies and during post-harvest senescence. Expression in normal development was significantly up-regulated in developmental stages 5 and 6. During post-harvest senescence, the expression of urease was mainly observed in the stipe tissue; expression decreased on the first day and remained at a basal level through the remaining sampling period.
authors.affiliation: Department of Microbiology, IWWR Radboud University Nijmegen, Toernooiveld 1, 6525 ED, Nijmegen, The Netherlands.
authors.forename: Matthijs J M
authors.initials: MJ
authors.lastname: Wagemaker
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Eastwood
authors.forename: Chris
authors.initials: C
authors.lastname: van der Drift
authors.forename: Mike S M
authors.initials: MS
authors.lastname: Jetten
authors.forename: Kerry
authors.initials: K
authors.lastname: Burton
authors.forename: Leo J L D
authors.initials: LJ
authors.lastname: Van Griensven
authors.forename: Huub J M
authors.initials: HJ
authors.lastname: Op den Camp
mesh_terms: D000364:Agaricus / Q000201:enzymology* / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014510:Urease / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D012333:RNA, Messenger; D014510:Urease