Dictyostelium amoebae lacking an F-box protein form spores rather than stalk in chimeras with wild type

Dictyostelium amoebae lacking an F-box protein form spores rather than stalk in chimeras with wild type

Department of Anatomy and Cell Biology, Columbia University, 630 West 168th Street, New York, NY 10032

Communicated by J. T. Bonner, Princeton University, Princeton, NJ (received for review November 10, 1999)

Abstract

Using a selection for Dictyostelium mutants that preferentially form spores, we have recovered a mutant called CheaterA. In chimeras with isogenic wild-type cells, the CheaterA mutant preferentially forms viable spores rather than inviable stalk cells. The mutant causes wild-type cells that have begun to express spore-specific genes to accumulate in the prestalk compartment of the developing organism. In the wild-type cells, the chtA transcript is absent in growing cells and appears early in development. No transcript was detected in the mutant by Northern blot. The chtA gene codes for a protein with an F-box and WD40 domains. This class of protein usually forms part of an Skp1, cullin, F-box (SCF) complex that targets specific protein substrates for ubiquitination and degradation.

Footnotes

↵ * To whom reprint requests should be addressed. E-mail: he28{at}columbia.edu (H.L.E.) or rhk2{at}columbia.edu (R.H.K.).
↵ † H.L.E. and D.N.D. contributed equally to this work.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. AF151111 and AF151112).
Article published online before print: Proc. Natl. Acad. Sci. USA, 10.1073/pnas.050005097.
Article and publication date are at www.pnas.org/cgi/doi/10.1073/pnas.050005097
Abbreviations:

REMI,

restriction enzyme-mediated integration;

β-gal,

β-galactosidase;

GFP,

green fluorescent protein