Open AccessTargeted substrate degradation by Kelch controls the actin cytoskeleton during ring canal expansion
Author(s) -
Andrew M. Hudson,
Katelynn M. Mannix,
Julianne A. Gerdes,
Molly C. Kottemann,
Lynn Cooley
Publication year - 2018
Publication title -
development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.15
H-Index - 36
eISSN - 1477-9129
pISSN - 0950-1991
DOI - 10.1242/dev.169219
Subject(s) - cullin , biology , cytoskeleton , microbiology and biotechnology , proteasome , ubiquitin ligase , actin , ubiquitin , tandem affinity purification , actin cytoskeleton , proteolysis , biochemistry , enzyme , affinity chromatography , gene , cell
During Drosophila oogenesis, specialized actin-based structures called ring canals form and expand to accommodate growth of the oocyte. Previous work demonstrated that Kelch and Cullin 3 function together in a Cullin 3-RING ubiquitin ligase complex (CRL3Kelch) to organize the ring canal cytoskeleton, presumably by targeting a substrate for proteolysis. Here, we use tandem affinity purification followed by mass spectrometry to identify HtsRC as the CRL3Kelch ring canal substrate. CRISPR-mediated mutagenesis of HtsRC revealed its requirement in the recruitment of the ring canal F-actin cytoskeleton. We present genetic evidence consistent with HtsRC being the CRL3Kelch substrate, as well as biochemical evidence indicating that HtsRC is ubiquitylated and degraded by the proteasome. Finally, we identify a short sequence motif in HtsRC that is necessary for Kelch binding. These findings uncover an unusual mechanism during development wherein a specialized cytoskeletal structure is regulated and remodeled by the ubiquitin-proteasome system.