Implicating SCF complexes in organogenesis in Caenorhabditis elegans.
Development of the Caenorhabditis elegans foregut (pharynx) is regulated by a network of proteins that includes the Retinoblastoma protein (pRb) ortholog LIN-35; the ubiquitin pathway components UBC-18 and ARI-1; and PHA-1, a cytoplasmic protein. Loss of pha-1 activity impairs pharyngeal development and body morphogenesis, leading to embryonic arrest. We have used a genetic suppressor approach to dissect this complex pathway. The lethality of pha-1 mutants is suppressed by loss-of-function mutations in sup-35/ztf-21 and sup-37/ztf-12, which encode Zn-finger proteins, and by mutations in sup-36. Here we show that sup-36 encodes a divergent Skp1 family member that binds to several F-box proteins and the microtubule-associated protein PLT-1/τ. Like SUP-35, SUP-36 levels were negatively regulated by UBC-18-ARI-1. We also found that SUP-35 and SUP-37 physically associated and that SUP-35 could bind microtubules. Thus, SUP-35, SUP-36, and SUP-37 may function within a pathway or complex that includes cytoskeletal components. Additionally, SUP-36 may regulate the subcellular localization of SUP-35 during embryogenesis. We carried out a genome-wide RNAi screen to identify additional regulators of this network and identified 39 genes, most of which are associated with transcriptional regulation. Twenty-three of these genes acted via the LIN-35 pathway. In addition, several S-phase kinase-associated protein (Skp)1-Cullin-F-Box (SCF) components were identified, further implicating SCF complexes as part of the greater network controlling pharyngeal development.
Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming 82071.
Stanley R G
SR
Polley
Aleksandra
A
Kuzmanov
Jujiao
J
Kuang
Jonathan
J
Karpel
Vladimir
V
Lažetić
Evguenia I
EI
Karina
Bethany L
BL
Veo
David S
DS
Fay
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism*; D002874:Chromosome Mapping; D004268:DNA-Binding Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D008025:Ligases / Q000235:genetics; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D038081:Organogenesis / Q000235:genetics*; D010614:Pharynx / Q000196:embryology; D034622:RNA Interference; D034741:RNA, Small Interfering; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D044767:Ubiquitin-Protein Ligases / Q000235:genetics
D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; C489033:PHA-1 protein, C elegans; D034741:RNA, Small Interfering; D012097:Repressor Proteins; C576145:ZTF-21 protein, C elegans; C116485:lin-35 protein, C elegans; D044767:Ubiquitin-Protein Ligases; C513732:ari-1 protein, C elegans; D008025:Ligases; C476242:Ubc-18 protein, C elegans
Caenorhabditis elegans; F-box; Skp1 pharynx; ari-1; lin-35; morphogenesis; pha-1; ptl-1; sup-35; sup-36; sup-37; ubc-18