Sensing of cardiolipin exposure on plasma membranes of apoptotic cells by EryA-mCherry protein

Žeželj, Luka (author), Bele, Tadeja (author), Panevska, Anastasija (author), Bajc, Gregor (author), Kejžar, Jan (author), Bahun, Miha (author), Poklar Ulrih, Nataša (author), Levak, Valentina (author), Skočaj, Matej (author), Popošek, Larisa Lara (author), Veranič, Peter (author), Resnik, Nataša (author), Sepčić, Kristina (author)

Erylysin A (EryA), an aegerolysin protein produced by the edible king oyster mushroom (Pleurotus eryngii), interacts strongly with an invertebrate-specific membrane sphingolipid ceramide phosphoethanolamine. Recently, a fluorescently fused variant of EryA was shown to bind to artificial and bacterial lipid membranes containing cardiolipin (CL). This tetra-acylated glycerophospholipid, present in bacteria and in inner mitochondrial mem-branes of eukaryotic cells, was shown to be externalized to the plasma membrane surface during the process of apoptosis. In this work, we evaluated the interaction of EryA-mCherry with CL-containing artificial lipid vesicles and with mammalian cells undergoing apoptosis and compared its binding affinity and specificity to that of the well-established apoptosis marker, annexin V-FITC. Our results show that, in contrast to annexin V-FITC, which binds several negatively charged glycerophospholipids, EryA-mCherry specifically recognizes and binds CL in artificial membrane systems. However, this binding of EryA-mCherry to CL-supplemented membranes is less effective (K$_D$ = 4.7 ±  1.6 μM) than that of annexin V-FITC, whose binding is observed at nanomolar concentrations. Experiments using mammalian cells showed the ability of EryA-mCherry to selectively label the membranes of apoptotic cells, binding to the same membrane regions as anti-CL antibodies and annexin V-FITC. Our data suggest that EryA-mCherry might be used as a marker of early apoptosis, as well as a marker of CL in biological and artificial lipid membranes.

• Language: English
• Keywords: aegerolysin, annexin V, apoptosis marker, cardiolipin, Pleurotus
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty; MF - Faculty of Medicine
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: Str. 1150-1167
• Numbering: Vol. 293, iss. 4
• PID: 20.500.12556/RUL-180918
• UDC: 577.112:577.29:601.2
• ISSN on article: 1742-4658
• DOI: 10.1111/febs.70290
• COBISS.SI-ID: 254650115
• Publication date in RUL: 19.03.2026

Record is a part of a journal

• Title: FEBS journal
• Shortened title: FEBS j.
• Publisher: Wiley, Federation of European Biochemical Societies
• ISSN: 1742-4658
• COBISS.SI-ID: 19644455

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: lipidne membrane, kardiolipin, egerolizini, biološki označevalci