α-actinin accounts for the bioactivity of actin preparations in inducing STAT target genes in Drosophila melanogaster

Journal Article: eLifeYear Published: (2018) Volume Number: 7, Article Number: e38636

Authors

Gordon,Oliver; Henry,Conor M; Srinivasan,Naren; Ahrens,Susan; Franz,Anna; Deddouche,Safia; Chakravarty,Probir; Phillips,David; George,Roger; Kjaer,Svend; Frith,David; Snijders,Ambrosius P; Valente,Rita S; Simoes da Silva,Carolina J; Teixeira,Luis; Thompson,Barry; Dionne,Marc S; Wood,Will; Reis e Sousa,Caetano

Damage-associated molecular patterns (DAMPs) are molecules exposed or released by dead cells that trigger or modulate immunity and tissue repair. In vertebrates, the cytoskeletal component F-actin is a DAMP specifically recognised by DNGR-1, an innate immune receptor. Previously we suggested that actin is also a DAMP in by inducing STAT-dependent genes (<xref ref-type="bibr" rid="bib10">Srinivasan et al., 2016</xref>). Here, we revise that conclusion and report that α-actinin is far more potent than actin at inducing the same STAT response and can be found in trace amounts in actin preparations. Recombinant expression of actin or α-actinin in bacteria demonstrated that only α-actinin could drive the expression of STAT target genes in . The response to injected α-actinin required the same signalling cascade that we had identified in our previous work using actin preparations. Taken together, these data indicate that α-actinin rather than actin drives STAT activation when injected into .