Germinal Center Kinases SmKIN3 and SmKIN24 Are Associated with the Sordaria macrospora Striatin-Interacting Phosphatase and Kinase (STRIPAK) Complex

PLoS One. 2015 Sep 29;10(9):e0139163. doi: 10.1371/journal.pone.0139163. eCollection 2015.

Abstract

The striatin-interacting phosphatase and kinase (STRIPAK) complex is composed of striatin, protein phosphatase PP2A and protein kinases that regulate development in animals and fungi. In the filamentous ascomycete Sordaria macrospora, it is required for fruiting-body development and cell fusion. Here, we report on the presence and function of STRIPAK-associated kinases in ascomycetes. Using the mammalian germinal center kinases (GCKs) MST4, STK24, STK25 and MINK1 as query, we identified the two putative homologs SmKIN3 and SmKIN24 in S. macrospora. A BLASTP search revealed that both kinases are conserved among filamentous ascomycetes. The physical interaction of the striatin homolog PRO11 with SmKIN3 and SmKIN24 were verified by yeast two-hybrid (Y2H) interaction studies and for SmKIN3 by co-Immunoprecipitation (co-IP). In vivo localization found that both kinases were present at the septa and deletion of both Smkin3 and Smkin24 led to abnormal septum distribution. While deletion of Smkin3 caused larger distances between adjacent septa and increased aerial hyphae, deletion of Smkin24 led to closer spacing of septa and to sterility. Although phenotypically distinct, both kinases appear to function independently because the double-knockout strain ΔSmkin3/ΔSmkin24 displayed the combined phenotypes of each single-deletion strain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Calmodulin-Binding Proteins / metabolism
  • Fruiting Bodies, Fungal / growth & development
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Gene Knockout Techniques
  • Germinal Center Kinases
  • Protein Phosphatase 2 / genetics
  • Protein Phosphatase 2 / metabolism*
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Sequence Alignment
  • Sordariales / enzymology*

Substances

  • Calmodulin-Binding Proteins
  • Fungal Proteins
  • Germinal Center Kinases
  • Protein Serine-Threonine Kinases
  • Protein Phosphatase 2

Grants and funding

Deutsche Forschungsgemeinschaft (DFG) (Grants PO523/4-1, PO523/4-2) SP. SF and EJR were supported by the Göttingen Graduate School for Neurosciences, Biophysics und Molecular Biosciences (Deutsche Forschungsgemeinschaft Grants GSC 226/1, GSC 226/2), EJR was supported by the Hans-Böckler Stiftung (Förder-Nr 377645). The authors acknowledge support by the Open Access Publication Funds of the Göttingen University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.