Putative membrane components of signal transduction pathways for ambient pH regulation in Aspergillus and meiosis in saccharomyces are homologous.
The zinc finger regions of the Aspergillus nidulans PacC transcription factor, mediating regulation of gene expression by ambient pH, and the Saccharomyces cerevisiae Rim1p transcription factor, mediating control of meiosis and invasiveness, are homologous and both transcription factors undergo proteolytic processing of the C-terminus for conversion to the functional form. In both cases, functioning of a signal transduction pathway involving several gene products is a necessary prerequisite for processing. We now show that the Aspergillus PalI pH signal transduction component is homologous to the Saccharomyces Rim9p meiotic signal transduction component throughout a region containing four hydrophobic, putative membrane-spanning segments. This suggests that PalI might be a membrane sensor for ambient pH. Deletion of the palI gene established that the less extreme phenotype of palI mutations compared with mutations in the other five genes of the pH signalling pathway is a general feature of palI mutations.
Denison
S H
SH
Department of Infectious Diseases, Imperial College School of Medicine at Hammersmith Hospital, Ducane Road, London W12 ONN, UK.
Negrete-Urtasun
S
S
Mingot
J M
JM
Tilburn
J
J
Mayer
W A
WA
Goel
A
A
Espeso
E A
EA
Peñalva
M A
MA
Arst
H N
HN
D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008540:Meiosis; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; C115834:PALI protein, Emericella nidulans; C092394:PacC protein, Aspergillus; C489601:RIM101 protein, S cerevisiae; C115786:RIM9 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C024406:endodeoxyribonuclease HpaI; C024408:endodeoxyribonuclease SacI; D015252:Deoxyribonucleases, Type II Site-Specific