SEPA-1 Mediates the Specific Recognition and Degradation of P Granule Components by Autophagy in C. elegans

National Institute of Biological Sciences, Beijing 102206, P.R. China.
Cell (Impact Factor: 33.12). 02/2009; 136(2):308-21. DOI: 10.1016/j.cell.2008.12.022
Source: PubMed

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.


Available from: Kai Zhang, Nov 14, 2014
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