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<oai_dc:dc schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
<dc:title>Interconnections between the Cation/Alkaline pH-Responsive Slt and the Ambient pH Response of PacC/Pal Pathways in Aspergillus nidulans</dc:title>
<dc:creator>Picazo, Irene</dc:creator>
<dc:creator>Espeso, Eduardo A.</dc:creator>
<dc:description>In the filamentous ascomycete <i>Aspergillus nidulans</i>, at least three high hierarchy transcription factors are required for growth at extracellular alkaline pH: SltA, PacC and CrzA. Transcriptomic profiles depending on alkaline pH and SltA function showed that <i>pacC</i> expression might be under SltA regulation. Additional transcriptional studies of PacC and the only pH-regulated <i>pal</i> gene, <i>palF</i>, confirmed both the strong dependence on ambient pH and the function of SltA. The regulation of <i>pacC</i> expression is dependent on the activity of the zinc binuclear (C6) cluster transcription factor PacX. However, we found that the ablation of <i>sltA</i> in the <i>pacX<sup>−</sup></i> mutant background specifically prevents the increase in <i>pacC</i> expression levels without affecting PacC protein levels, showing a novel specific function of the PacX factor. The loss of <i>sltA</i> function causes the anomalous proteolytic processing of PacC and a reduction in the post-translational modifications of PalF. At alkaline pH, in a null <i>sltA</i> background, PacC<sup>72kDa</sup> accumulates, detection of the intermediate PacC<sup>53kDa</sup> form is extremely low and the final processed form of 27 kDa shows altered electrophoretic mobility. Constitutive ubiquitination of PalF or the presence of alkalinity-mimicking mutations in <i>pacC</i>, such as <i>pacC<sup>c</sup>14</i> and <i>pacC<sup>c</sup>700</i>, resembling PacC<sup>53kDa</sup> and PacC<sup>27kDa</sup>, respectively, allowed the normal processing of PacC but did not rescue the alkaline pH-sensitive phenotype caused by the null <i>sltA</i> allele. Overall, data show that Slt and PacC/Pal pathways are interconnected, but the transcription factor SltA is on a higher hierarchical level than PacC on regulating the tolerance to the ambient alkalinity in <i>A. nidulans</i>.</dc:description>
<dc:date>2024-05-04T09:49:11Z</dc:date>
<dc:date>2024-05-04T09:49:11Z</dc:date>
<dc:date>2024-04-08</dc:date>
<dc:date>2024-05-04T09:49:11Z</dc:date>
<dc:type>artículo</dc:type>
<dc:identifier>doi: 10.3390/cells13070651</dc:identifier>
<dc:identifier>Cells 13 (7): 651 (2024)</dc:identifier>
<dc:identifier>http://hdl.handle.net/10261/355792</dc:identifier>
<dc:rights>open</dc:rights>
<dc:publisher>Multidisciplinary Digital Publishing Institute</dc:publisher>
</oai_dc:dc>