Table 3 Biological functions of the 60 essential genes
let-NameChrGene NameProtein FunctionPathwayEvolutionary Conservation
let-752IIIlin-13Zinc-regulated transcription factorIn C. elegans, LIN-13 is involved in the tumor suppressor Rb-mediated transcriptional control process that leads to repression of vulval fates.N
let-798IIIwrm-1C. elegans β-catenin-like proteinIn C. elegans, wrm-1 functions in noncanonical Wnt signaling pathways that specify cell fates in the early embryo.N
let-342Vpmt-2Enzyme: phosphoethanolamine N-methyltransferasePMT-2 lacks known mammalian orthologs, but has orthologs in the parasitic nematodes: fish, plants, and bacteria. PMT-1 only catalyzes the conversion of phosphoethanolamine to phospho-monomethylethanolamine, which is the first step in the PEAMT-pathway.N
let-757/let-821IIIfbn-1Extracellular matrix protein fibrillinFibrillin is a glycoprotein, which is essential for the formation of elastic fibers found in connective tissues.N, I, M
let-782IIItag-189UnknownUnknownN, I, M
let-827IIIcee-1UnknownUnknownN, I, M
let-327VT08B1.1Member of solute carriers familyPredicted to have transmembrane transporter activity.N, I, M
let-344Vsos-1Son of sevenless homologIts ortholog in mouse is a catalytic component of a trimeric complex that participates in transduction of signals from Ras to Rac by promoting the Rac-specific guanine nucleotide exchange factor activity. SOS-1 is involved in multiple Ras-dependent signaling pathways, which also interacts with LET-23 and LET-60 during vulval development.N, I, M
let-348Vrft-1Member of solute carriers family, riboflavin transporterIn C. elegans, rft-1 exhibits riboflavin transporter activity and is involved in embryo development and receptor-mediated endocytosis.N, I, M
let-423Vmig-6Highly similar to the extracellular matrix proteins papilin and lacuninIn C. elegans, MIG-6 activity is required for the ventral to dorsal phase of distal tip cell migration.N, I, M
let-440Vncx-2Sodium/calcium exchangersMediates the electrogenic exchange of Ca2+ against Na+ ions across the cell membrane, thereby contributes to the regulation of cytoplasmic Ca2+ levels and Ca2+-dependent cellular processes.N, I, M
let-702IIIhmgr-1Enzyme: 3-hydroxy-3-methylglutaryl-coenzyme A reductaseHMG-CoA reductase catalyzes the conversion of HMG-CoA to mevalonate, which is a rate-limiting step in sterol biosynthesis.N, I, M, F
let-712IIIprp-8mRNA splicing: pre-mRNA-processing-splicing factorIts ortholog in yeast is a component of the U4/U6-U5 snRNP complex and participates in spliceosomal assembly through its interaction with the U1 snRNA.N, I, M, F
let-732IIIrpb-2Enzyme: RNA polymerase II (B) subunitThe second largest subunit B150 of RNA polymerase II is the enzyme that produces the primary transcript.N, I, M, F
let-736IIIcdk-12Enzyme: cyclin-dependent kinaseIts ortholog in yeast phosphorylates both the RNA pol II subunit to affect transcription, and the ribosomal protein to increase translational fidelity.N, I, M, F
let-741IIIrars-1Enzyme: arginyl(R) aminoacyl tRNA synthetase in mitochondriaThe tRNA synthetase catalyzes the attachment of an amino acid to its cognate transfer RNA molecule.N, I, M, F
let-743IIIZK686.2Enzyme: ATP-dependent RNA helicaseIts orthologs in yeast and human are involved in the biogenesis of ribosomal subunits.N, I, M, F
let-747IIIalgn-1Enzyme: chitobiosyldiphosphodolichol β-mannosyltransferaseMannosyltransferase is involved in asparagine-linked glycosylation in the endoplasmic reticulum.N, I, M, F
let-753IIIC34E10.10Ribosome-related protein: rRNA-processing proteinThe protein is involved in ribosomal subunit biogenesis.N, I, M, F
let-763IIIT08A11.2mRNA splicing: splicing factor 3B subunit 1U2-snRNP associated splicing factor forms extensive associations with the branch site-3′ splice site-3′ exon region upon prespliceosome formation.N, I, M, F
let-764IIIbyn-1Mammalian bystin (adhesion protein) related proteinIts ortholog in yeast is required for pre-rRNA processing and 40S ribosomal subunit synthesis.N, I, M, F
let-771IIIrfl-1Enzyme: ubiquitin activating enzymeRFL-1 activity is required for proper cytokinesis and spindle orientation.N, I, M, F
let-774IIIrps-3Ribosome-related protein: ribosomal protein, small subunitProtein component of the small ribosomal subunit involved in protein biosynthesis.N, I, M, F
let-784IIIgop-3Component of the Sorting and Assembly Machinery (SAM) complexSAM complex binds precursors of beta-barrel proteins and facilitates their outer membrane insertion.N, I, M, F
let-786IIIunc-116Kinesin-related motor proteinIts ortholog in yeast is required for mitotic spindle assembly and chromosome segregation.N, I, M, F
let-799IIIddx-23Enzyme: ATP-dependent RNA helicaseIts ortholog in yeast is involved in mRNA decay and rRNA processing.N, I, M, F
let-826IIImrps-18CRibosome-related protein: ribosomal protein (small) in mitochondriaRibosomal subunit biogenesisN, I, M, F
let-829IIIatp-2Enzyme: mitochondrial ATP synthase subunitEvolutionarily conserved enzyme complex that is required for ATP synthesis.N, I, M, F
let-832IIIF09F7.4Enzyme: 3-hydroxyisobutyryl-CoA hydrolaseBiological process unknownN, I, M, F
let-972IIIhsp-110Heat shock proteinIts ortholog in yeast is a ATPase component of the heat shock protein Hsp90 chaperone complex and serves as nucleotide exchange factor to load ATP onto the SSA class of cytosolic Hsp70s.N, I, M, F
let-326Vrab-1Enzyme: Rab family GTPaseIntracellular vesicle trafficking, such as the ER-to-Golgi step of the secretory pathway.N, I, M, F
let-331Vprx-6Peroxisomal biogenesis factorIts ortholog in yeast heterodimerizes with Pex1p and participates in the recycling of the peroxisomal signal receptor from the peroxisomal membrane to the cystosol.N, I, M, F
let-332VC05C8.7Enzyme: Mannose phosphate isomeraseIts ortholog in yeast catalyzes the interconversion of fructose-6-P and mannose-6-P, which is required for early steps in protein mannosylation.N, I, M, F
let-334Vslc-17.8Member of solute carriers familyPredicted to have transmembrane transporter activity.N, I, M, F
let-335VC37C3.2Translation initiation factorBased on the homology to yeast, the products of C37C3.2 are predicted to function during translation initiation as GTPase activators to stimulate GTP hydrolysis by eIF2-GTP-Met-tRNAi.N, I, M, F
let-338Vrpac-40Enzyme: RNA polymerase I/III (A/C) shared subunitCommon component of RNA polymerases I and III, which synthesize ribosomal RNA precursors and small RNAs, such as 5S rRNA and tRNAs.N, I, M, F
let-343Vcpsf-2Cleavage and polyadenylation specificity factorRequired for 3′ processing, splicing, and transcriptional termination of mRNAs and snoRNAs.N, I, M, F
let-346Vsoap-1HEAT repeat-containing proteinSOAP is involved in a pathway that controls the apical delivery of E-cad and morphogenesis.N, I, M, F
let-350VC37H5.5Nucleolar complex protein-like DNA replication regulatorIts ortholog in yeast binds to chromatin at active replication origins and is required for pre-RC formation as well as maintenance during DNA replication licensing.N, I, M, F
let-402Verfa-1Translation termination factorSubunit of the heterodimeric translation release factor complex involved in the release of nascent polypeptides from ribosomes.N, I, M, F
let-408Vsnap-1α-soluble NSF attachment proteinIts ortholog in mouse is required for vesicular transport between the endoplasmic reticulum and the Golgi apparatus.N, I, M, F
let-409Vasns-1Enzyme: asparagine synthase (glutamine-hydrolyzing)Catalyzes the synthesis of L-asparagine from L-aspartate in the asparagine biosynthetic pathway.N, I, M, F
let-410Vdlst-1Enzyme: dihydrolipoamide S-succinyltransferaseIts ortholog in yeast is a component of the mitochondrial alpha-ketoglutarate dehydrogenase complex, which catalyzes the oxidative decarboxylation of alpha-ketoglutarate to succinyl-CoA in the TCA cycle.N, I, M, F
let-411Vxpo-1Exportin-1, an importin-β-like protein orthologous to Drosophila, vertebrates, and yeast exportin-1/CRM1XPO-1 is predicted to function as a nuclear export receptor for proteins containing leucine-rich nuclear export signals.N, I, M, F
let-415Vhsp-6Nuclear-encoded mitochondrion-specific chaperone that is a member of the DnaK/Hsp70 superfamily of molecular chaperonesIn C. elegans, hsp-6 is involved in the mitochondrial unfolded protein response.N, I, M, F
let-417Vceh-34Homeobox proteinIn C. elegans, ceh-34 activity is required for regulation of the programmed cell death of a pharyngeal neuron, the sister of the M4 motor neuron.N, I, M, F
let-419Vpqn-51Transcription initiation factor IIAIts ortholog in yeast is involved in transcriptional activation and acts as antirepressor or coactivator.N, I, M, F
let-420Vadss-1Enzyme: adenylosuccinate synthetaseCatalyzes the first step in the synthesis of adenosine monophosphate from inosine 5′monophosphate during purine nucleotide biosynthesis.N, I, M, F
let-422Vhmgs-1Enzyme: hydroxymethylglutaryl-CoA synthaseIts ortholog in yeast catalyzes the formation of HMG-CoA from acetyl-CoA and acetoacetyl-CoA.N, I, M, F
let-424Vvars-1Enzyme: valyl-aminoacyl tRNA synthetase in mitochondriaThe tRNA synthetase catalyzes the attachment of an amino acid to its cognate transfer RNA molecule.N, I, M, F
let-439VM03F8.3mRNA splicing: crooked neck pre-mRNA splicing factorThe crooked neck gene of Drosophila is essential for embryogenesis and is thought to be involved in cell cycle progression and pre-mRNA splicing.N, I, M, F
let-442VC05C8.2Ribosome-related protein: small subunit processome componentA nucleolar protein required for rRNA synthesis and ribosomal assembly.N, I, M, F
let-447Vegl-8Enzyme: phospholipase C βIn yeast, the ortholog (Plc1p) and inositol polyphosphates are required for acetyl-CoA homeostasis, which regulates global histone acetylation.N, I, M, F
let-459Vhpo-18Enzyme: ATP synthaseUnknownN, I, M, F
let-470VF11A3.2Translation initiation factorThese proteins help stabilize the formation of the functional ribosome around the start codon and also provide regulatory mechanisms in translation initiation.N, I, M, F
  • The table is sorted by evolutionary conservation, chromosome (Chr), and lethal name (let-Name). N, nematodes; I, invertebrates (Drosophila); M, mammals (mouse, human); F, fungi (Saccharomycetaceae).