Identification of new OPA1 cleavage site reveals that short isoforms regulate mitochondrial fusion

Ruohan Wang, Prashant Mishra, Spiros D. Garbis, Annie Moradian, Michael J. Sweredoski, David C. Chan

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


OPA1, a large GTPase of the dynamin superfamily, mediates fusion of the mitochondrial inner membranes, regulates cristae morphology, and maintains respiratory chain function. Inner membrane–anchored long forms of OPA1 (l-OPA1) are proteolytically processed by the OMA1 or YME1L proteases, acting at cleavage sites S1 and S2, respectively, to produce short forms (s-OPA1). In both mice and humans, half of the mRNA splice forms of Opa1 are constitutively processed to yield exclusively s-OPA1. However, the function of sOPA1 in mitochondrial fusion has been debated, because in some stress conditions, s-OPA1 is dispensable for fusion. By constructing cells in which the Opa1 locus no longer produces transcripts with S2 cleavage sites, we generated a simplified system to identify the new YME1L-dependent site S3 that mediates constitutive and complete cleavage of OPA1. We show that mitochondrial morphology is highly sensitive to the ratio of l-OPA1 to s-OPA1, indicating that s-OPA1 regulates mitochondrial fusion.

Original languageEnglish (US)
Pages (from-to)157-168
Number of pages12
JournalMolecular biology of the cell
Issue number2
StatePublished - Jan 2021

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Identification of new OPA1 cleavage site reveals that short isoforms regulate mitochondrial fusion'. Together they form a unique fingerprint.

Cite this