Expression of the Aspergillus fumigatus rheb homologue, rhbA, is induced by nitrogen starvation.
A gene encoding a ras protein with homology to the rheb family was cloned from Aspergillus fumigatus. Although conserved ras domains are present, the predicted RhbA protein sequence deviates from the ras consensus in a manner that is characteristic of rheb proteins. The invariant Gly-Gly in the first GTP-binding domain of ras proteins is replaced by Arg-Ser in RhbA, and a conserved Asp in the effector region of ras proteins is replaced by Asn in RhbA. The rhbA mRNA was detected throughout the A. fumigatus asexual developmental cycle, and accumulated over 5-fold in response to nitrogen starvation. The rhbA gene was able to complement the canavanine hypersensitivity of Saccharomyces cerevisiae Deltarhb1 mutants, suggesting that the two proteins share overlapping function.
Department of Pathology and Laboratory Medicine, University of Cincinnati, P.O. Box 670529, Cincinnati, OH 45267-0529, USA.
John C
JC
Panepinto
Brian G
BG
Oliver
Thomas W
TW
Amlung
David S
DS
Askew
Judith C
JC
Rhodes
D000595:Amino Acid Sequence; D001232:Aspergillus fumigatus / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics; D019204:GTP-Binding Proteins / Q000235:genetics; D015870:Gene Expression; D005800:Genes, Fungal; D011905:Genes, ras / Q000235:genetics*; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics; D009584:Nitrogen / Q000172:deficiency / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D005656:Fungal Proteins; D009479:Neuropeptides; D012333:RNA, Messenger; D019204:GTP-Binding Proteins; D020559:Monomeric GTP-Binding Proteins; D009584:Nitrogen