title: SEPA-1 mediates the specific recognition and degradation of P granule components by autophagy in C. elegans.
abstract: How autophagy, an evolutionarily conserved intracellular catabolic system for bulk degradation, selectively degrades protein aggregates is poorly understood. Here, we show that several maternally derived germ P granule components are selectively eliminated by autophagy in somatic cells during C. elegans embryogenesis. The activity of sepa-1 is required for the degradation of these P granule components and for their accumulation into aggregates, termed PGL granules, in autophagy mutants. SEPA-1 forms protein aggregates and is also a preferential target of autophagy. SEPA-1 directly binds to the P granule component PGL-3 and also to the autophagy protein LGG-1/Atg8. SEPA-1 aggregates consistently colocalize with PGL granules and with LGG-1 puncta. Thus, SEPA-1 functions as a bridging molecule in mediating the specific recognition and degradation of P granule components by autophagy. Our study reveals a mechanism for preferential degradation of protein aggregates by autophagy and emphasizes the physiological significance of selective autophagy during animal development.
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, P.R. China.
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Zhang
authors.forename: Libo
authors.initials: L
authors.lastname: Yan
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhou
authors.forename: Peiguo
authors.initials: P
authors.lastname: Yang
authors.forename: E
authors.initials: E
authors.lastname: Tian
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Song
authors.forename: Jinghua
authors.initials: J
authors.lastname: Han
authors.forename: Long
authors.initials: L
authors.lastname: Miao
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001343:Autophagy; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000378:metabolism*; D012734:Disorders of Sex Development; D005111:Extrachromosomal Inheritance; D008297:Male; D008969:Molecular Sequence Data; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; C534959:PGL-3 protein, C elegans; D016601:RNA-Binding Proteins; C534958:SEPA-1 protein, C elegans