RcoA has pleiotropic effects on Aspergillus nidulans cellular development

Abstract

Aspergillus nidulans rcoA encodes a member of the WD repeat family of proteins. The RcoA protein shares sequence similarity with other members of this protein family, including the Saccharomyces cerevisiae Tup1p and Neurospora crassa RCO1. Tup1p is involved in negative regulation of an array of functions including carbon catabolite repression. RCO1 functions in regulating pleiotropic developmental processes, but not carbon catabolite repression. In A. nidulans, deletion of rcoA (ΔrcoA), a recessive mutation, resulted in gross defects in vegetative growth, asexual spore production and sterigmatocystin (ST) biosynthesis. Expression of the asexual and ST pathway‐specific regulatory genes, brlA and aflR, respectively, but not the signal transduction genes (i.e. flbA, fluG or fadA) regulating brlA and aflR expression was delayed (brlA) or eliminated (aflR) in a ΔrcoA strain. Overexpression of aflR in a ΔrcoA strain could not rescue normal expression of downstream targets of AflR. CreA‐dependent carbon catabolite repression of starch and ethanol utilization was only weakly affected in a ΔrcoA strain. The strong role of RcoA in development, vegetative growth and ST production, compared with a relatively weak role in carbon catabolite repression, is similar to the role of RCO1 in N. crassa.

Molecular cloning and characterization of WdTUP1, a gene that encodes a potential transcriptional repressor important for yeast-hyphal transitions in Wangiella (Exophiala) dermatitidis

“…For example, in Neurospora crassa, the Tup1p ortholog rco-1 controls the mycelial repression of conidial gene expression, and mediates the repression of genes involved in several other processes (Yamashiro et al, 1996). Similarly, in Aspergillus nidulans, the Tup1p ortholog rcoA has pleiotropic effects on cellular development and controls asexual development (Hicks et al, 2001). Moreover, in Penicillium marneffei, TupA is involved in the repression of both spore and yeast morphogenesis (Todd et al, 2003).…”

TheAspergillus nidulans rcoAGene Is Required forveA-Dependent Sexual Development

“…The balance between vegetative growth, asexual development, and sexual development is tightly controlled (Tsitsigiannis et al 2004(Tsitsigiannis et al , 2005. The rcoA gene is required for normal vegetative growth and asexual development (Hicks et al 2001). We show here that rcoA is a pivotal sexual development regulator and lies downstream of veA in the sexual development pathway.…”

“…The genotypes of the strains used are: wild type (MH1: biA1; veA1), blA1 (A268: yA2; wA3 thiA4 cnxE16 adD3 blA1; veA1), and rcoAD (MH9748: biA1; rcoAD; veA1). MH9748 was derived from an outcross of AnrcoA (biA1; rcoAD argB2; methG1) (Hicks et al 2001). Crosses used segregating conidial color markers to distinguish hybrid and selfed cleistothecia by the appearance of color recombinants among the progeny.…”

“…Our crosses are not informative with respect to whether rcoAD nuclei can be contributed to the zygote from the female and male parent. The rcoA gene encodes a WD40 repeat protein with sequence similarity to the pleiotropic transcriptional repressors RCO1 from Neurospora crassa and TUP1 from Saccharomyces cerevisiae (Hicks et al 2001). RCO1 is required for female sexual development (Yamashiro et al 1996) and TUP1 is required for MATa sexual function (Mukai et al 1991).…”

“…LITERATURE CITED Andrianopoulos, A., and M. J. Hynes, 1988 a The rcoA gene (À1142 to 12299; GenBank accession no. AF197225) was subcloned as a 3.4-kb PstI fragment from pW03D10 (Hicks et al 2001) into pALX223, which contains the A. nidulans pyrG selectable marker in the backbone of pBluescriptSKÀ. The resulting plasmid, pRT5253, was transformed, using the protocol of Andrianopoulos and Hynes (1988), into MH10447 (biA1 pyrG89 veA1), and PyrG prototrophs were selected.…”