DIF-1 induces its own breakdown in Dictyostelium

Insall, R. , Nayler, O. and Kay, R. R. (1992) DIF-1 induces its own breakdown in Dictyostelium. EMBO Journal, 11(8), pp. 2849-2854. (PMID:1322291) (PMCID:PMC556764)

Abstract

DIF-1 is a novel chlorinated alkyl phenone which induces differentiation of prestalk cells in Dictyostelium discoideum. It is broken down and inactivated by a cytoplasmic enzyme, DIF-1 3(5)-dechlorinase (hereafter referred to as DIF-1 dechlorinase), which is found only in prestalk cells. We show that DIF-1 dechlorinase levels are induced at least 50-fold when cells are treated with DIF-1. This response is rapid--enzyme activity doubles within 15 min and is fully induced within an hour--and occurs early in development, before other prestalk markers can be induced by DIF-1. Maximum inducibility is seen towards the end of aggregation, when DIF-1 dechlorinase is barely detectable in uninduced cells. The dose-dependence reveals a threshold concentration of DIF-1 (15 nM) below which almost no response is seen. Cyclic AMP, which is the chemoattractant during aggregation and plays a key role in later development, suppresses the induction of DIF-1 dechlorinase by DIF-1. We conclude that induction of DIF-1 dechlorinase is one of the first steps on the developmental pathway which leads to prestalk cell differentiation, and suggest that the resulting negative feedback on DIF-1 levels is an important part of the mechanism by which cells decide whether to become prestalk or prespore cells.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Insall, Professor Robert
• Authors: Insall, R., Nayler, O., and Kay, R. R.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: EMBO Journal
• Publisher: EMBO Press
• ISSN: 0261-4189
• ISSN (Online): 1460-2075