Aspergillus nidulans ambient pH signaling does not require endocytosis
File(s)EC--pH reg does not require endocytosis.pdf (7.67 MB)
Accepted version
Author(s)
Lucena-Agell, D
Galindo, A
Arst, HN
Penalva, MA
Type
Journal Article
Abstract
Aspergillus nidulans (Pal) ambient pH signaling takes place in cortical structures containing components of the ESCRT pathway, which are hijacked by the alkaline pH-activated, ubiquitin-modified version of the arrestin-like protein PalF and taken to the plasma membrane. There, ESCRTs scaffold the assembly of dedicated Pal proteins acting downstream. The molecular details of this pathway, which results in the two-step proteolytic processing of the transcription factor PacC, have received considerable attention due to the key role that it plays in fungal pathogenicity. While current evidence strongly indicates that the pH signaling role of ESCRT complexes is limited to plasma membrane-associated structures where PacC proteolysis would take place, the localization of the PalB protease, which almost certainly catalyzes the first and only pH-regulated proteolytic step, had not been investigated. In view of ESCRT participation, this formally leaves open the possibility that PalB activation requires endocytic internalization. As endocytosis is essential for hyphal growth, nonlethal endocytic mutations are predicted to cause an incomplete block. We used a SynA internalization assay to measure the extent to which any given mutation prevents endocytosis. We show that none of the tested mutations impairing endocytosis to different degrees, including slaB1, conditionally causing a complete block, have any effect on the activation of the pathway. We further show that PalB, like PalA and PalC, localizes to cortical structures in an alkaline pH-dependent manner. Therefore, signaling through the Pal pathway does not involve endocytosis.
Date Issued
2015-04-03
Date Acceptance
2015-03-30
Citation
Eukaryotic Cell, 2015, 14 (6), pp.545-553
ISSN
1535-9778
Publisher
American Society for Microbiology
Start Page
545
End Page
553
Journal / Book Title
Eukaryotic Cell
Volume
14
Issue
6
Copyright Statement
© 2015, American Society for Microbiology. All Rights Reserved.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000355543000003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Microbiology
Mycology
Plasma-membrane
Transcription factor
Saccharomyces-cerevisiae
Mediated endocytosis
Actin cytoskeleton
Yeast
Protein
Gene
Pathway
Aspergillus nidulans
Cysteine Endopeptidases
Endocytosis
Endosomal Sorting Complexes Required for Transport
Fungal Proteins
Signal Transduction
Transcription Factors
Biological Sciences
Medical And Health Sciences
Publication Status
Published