A role for Jsn1p in recruiting the Arp2/3 complex to mitochondria in budding yeast.
Although the Arp2/3 complex localizes to the leading edge of motile cells, endocytic structures, and mitochondria in budding yeast, the mechanism for targeting the Arp2/3 complex to different regions in the cell is not well understood. We find that Jsn1p, a member of the PUF family of proteins, facilitates association of Arp2/3 complex to yeast mitochondria. Jsn1p localizes to punctate structures that align along mitochondria, cofractionates with a mitochondrial marker protein during subcellular fractionation, and is both protease sensitive and carbonate extractable in isolated mitochondria. Thus, Jsn1p is a peripheral membrane protein that is associated with the outer leaflet of the mitochondrial outer membrane. Jsn1p colocalized and coimmunoprecipitated with mitochondria-associated Arc18p-GFP, and purified Arp2/3 complex bound to isolated TAP-tagged Jsn1p. Moreover, deletion of JSN1 reduces the amount of Arc18p-GFP that colocalizes and is recovered with mitochondria twofold, and jsn1Delta cells exhibited defects in mitochondrial morphology and motility similar to those observed in Arp2/3 complex mutants. Thus, Jsn1p has physical interactions with mitochondria-associated Arp2/3 complex and contributes to physical and functional association of the Arp2/3 complex with mitochondria.
Fehrenbacher
Kammy L
KL
Department of Anatomy and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA.
Boldogh
Istvan R
IR
Pon
Liza A
LA
D051376:Actin-Related Protein 2-3 Complex; D000199:Actins / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism* / Q000502:physiology*; D017353:Gene Deletion; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology*; D004718:Saccharomycetales
D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; D005656:Fungal Proteins; C097438:JSN1 protein, S cerevisiae; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins