Mutational analysis of the pH signal transduction component PalC of Aspergillus nidulans supports distant similarity to BRO1 domain family members.
The alkaline ambient pH signal transduction pathway component PalC has no assigned molecular role. Therefore we attempted a gene-specific mutational analysis and obtained 55 new palC loss-of-function alleles including 24 single residue substitutions. Refined similarity searches reveal conserved PalC regions including one with convincing similarity to the BRO1 domain, denoted PCBROH, where clustering of mutational changes, including PCBROH key residue substitutions, supports its structural and/or functional importance. Since the BRO1 domain occurs in the multivesicular body (MVB) pathway protein Bro1/Vps31 and also the pH signal transduction protein PalA (Rim20), both of which interact with MVB component (ESCRT-III protein) Vps32/Snf7, this might reflect a further link between the pH response and endocytosis.
Tilburn
Joan
J
Department of Infectious Diseases, Faculty of Medicine, Imperial College London, United Kingdom. j.tilburn@imperial.ac.uk
Sánchez-Ferrero
Juan C
JC
Reoyo
Elena
E
Arst
Herbert N
HN
Peñalva
Miguel A
MA
D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000235:genetics*; D017124:Conserved Sequence / Q000235:genetics; D004252:DNA Mutational Analysis; D056827:Endosomal Sorting Complexes Required for Transport; D005656:Fungal Proteins / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D033921:Vesicular Transport Proteins / Q000235:genetics
C480237:Bro1 protein, S cerevisiae; D056827:Endosomal Sorting Complexes Required for Transport; D005656:Fungal Proteins; C121839:PALC protein, Emericella nidulans; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins