CHPA, a cysteine- and histidine-rich-domain-containing protein, contributes to maintenance of the diploid state in Aspergillus nidulans.
The alternation of eukaryotic life cycles between haploid and diploid phases is crucial for maintaining genetic diversity. In some organisms, the growth and development of haploid and diploid phases are nearly identical, and one might suppose that all genes required for one phase are likely to be critical for the other phase. Here, we show that targeted disruption of the chpA (cysteine- and histidine-rich-domain- [CHORD]-containing protein A) gene in haploid Aspergillus nidulans strains gives rise to chpA knockout haploids and heterozygous diploids but no chpA knockout diploids. A. nidulans chpA heterozygous diploids showed impaired conidiophore development and reduced conidiation. Deletion of chpA from diploid A. nidulans resulted in genome instability and reversion to a haploid state. Thus, our data suggest a vital role for chpA in maintenance of the diploid phase in A. nidulans. Furthermore, the human chpA homolog, Chp-1, was able to complement haploinsufficiency in A. nidulans chpA heterozygotes, suggesting that the function of CHORD-containing proteins is highly conserved in eukaryotes.
The Sainsbury Laboratory, John Innes Centre, Colney Lane, Norwich NR4 7UH, United Kingdom.
Ari
A
Sadanandom
Kim
K
Findlay
John H
JH
Doonan
Paul
P
Schulze-Lefert
Ken
K
Shirasu
D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000166:cytology / Q000235:genetics* / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism; D004171:Diploidy; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D018390:Gene Targeting; D006801:Humans; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D000099053:Histidine-Rich Glycoprotein
D002352:Carrier Proteins; C478383:Chp-1 protein, mouse; D005656:Fungal Proteins; D018832:Molecular Chaperones; D011506:Proteins; D000099053:Histidine-Rich Glycoprotein