title: Characterization of the non-sexual flocculation of fission yeast cells that results from the deletion of ribosomal protein L32.
abstract: We recently reported that deleting either of the two paralogous rpl32 genes resulted in non-sexual flocculation in fission yeast. This study represents the first report that these non-sexually flocculating fission yeast cells exhibit a thicker cell wall, an increased wall protein content with smeared glycosylated wall proteins, and increased cell wall polysaccharide content and adhesin-binding sugar residues (i.e. glucose, mannose and galactose). These changes reflect the wall features of flocculating cells that mediate recognition and connections between cells. Furthermore, this study demonstrates that this non-sexual flocculation is an adhesin-mediated process: (a) the transcription levels of several members of the Mam3/Map4 family of adhesins (i.e. PFL3, PFL7 and PFL6) and a Flo11-like adhesin protein are upregulated in rpl32-1Δ and rpl32-2Δ cells; (b) this non-sexual flocculation of rpl32-1Δ and rpl32-2Δ cells was eliminated by heating or enzyme digestion; (c) this non-sexual flocculation of rpl32-1Δ and rpl32-2Δ cells was enhanced by Ca(2+) and some other divalent metal ions, which stabilize the active conformation of adhesins; and (d) this non-sexual flocculation of rpl32-1Δ and rpl32-2Δ cells was competitively inhibited by glucose, galactose or mannose rather than only by galactose, as reported previously. Although different adhesin genes are selectively expressed under particular physiological or environmental conditions, the functions of these adhesins are the same and are interchangeable.
authors.affiliation: Jiangsu Key Laboratory for Microbes and Functional Genetics, Jiangsu Engineering and Technology Research Centre for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, People's Republic of China.
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Liu
authors.forename: Rongpeng
authors.initials: R
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Dong
authors.forename: Lezhi
authors.initials: L
authors.lastname: Bian
authors.forename: Xuesong
authors.initials: X
authors.lastname: Li
authors.forename: Sheng
authors.initials: S
authors.lastname: Yuan
mesh_terms: D002118:Calcium / Q000378:metabolism; D005427:Flocculation; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D017353:Gene Deletion; D005947:Glucose / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D012568:Schizosaccharomyces / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D012269:Ribosomal Proteins; C041806:ribosomal protein L32; D005947:Glucose; D002118:Calcium; D005690:Galactose
keywords: Schizosaccharomyces pombe; adhesins; asexual flocculation; cell wall; ribosomal protein L32