title: The hybrid type polyketide synthase SteelyA is required for cAMP signalling in early Dictyostelium development.
abstract: BACKGROUND
  In our previous study we found that the expression of stlA showed peaks both in the early and last stages of development and that a product of SteelyA, 4-methyl-5-pentylbenzene-1,3-diol (MPBD), controlled Dictyostelium spore maturation during the latter. In this study we focused on the role of SteelyA in early stage development.
  
  
  RESULTS
  Our stlA null mutant showed aggregation delay and abnormally small aggregation territories. Chemotaxis analysis revealed defective cAMP chemotaxis in the stlA null mutant. cAMP chemotaxis was restored by MPBD addition during early stage development. Assay for cAMP relay response revealed that the stlA null mutant had lower cAMP accumulation during aggregation, suggesting lower ACA activity than the wild type strain. Exogenous cAMP pulses rescued the aggregation defect of the stlA null strain in the absence of MPBD. Expression analysis of cAMP signalling genes revealed lower expression levels in the stlA null mutant during aggregation.
  
  
  CONCLUSIONS
  Our data indicate a regulatory function by SteelyA on cAMP signalling during aggregation and show that SteelyA is indispensable for full activation of ACA.
authors.affiliation: Graduate School of Science and Technology, Sophia University, Tokyo, Japan; Research Fellow of Japan Society for the Promotion of Science (DC2), Tokyo, Japan.
authors.forename: Takaaki B
authors.initials: TB
authors.lastname: Narita
authors.affiliation: College of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Zhi-hui
authors.initials: ZH
authors.lastname: Chen
authors.affiliation: College of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Pauline
authors.initials: P
authors.lastname: Schaap
authors.affiliation: Department of Materials and Life Sciences, Sophia University, Tokyo, Japan.
authors.forename: Tamao
authors.initials: T
authors.lastname: Saito
mesh_terms: D002633:Chemotaxis / Q000235:genetics; D000242:Cyclic AMP / Q000378:metabolism*; D004023:Dictyostelium / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015536:Down-Regulation; D017353:Gene Deletion; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000235:genetics
chemical_list: D015800:Protozoan Proteins; D048630:Polyketide Synthases; D000242:Cyclic AMP