Mitochondria as a sequestration site for incomplete TCRβ peptides: The TCRβ transmembrane domain is a sufficient mitochondrial targeting signal

► Truncated forms of TCRβ target mitochondria and induce apoptosis. ► Residues flanking the TMD of TCRβ are inessential for its mitochondrial targeting. ► The isolated TMD of TCRβ is a sufficient mitochondrial-targeting signal. ► Any TCRβ truncation, leaving an intact TMD, causes mitochondrial targeting. ► Mitochondria are a sequestration site for impaired TCR molecules.