Transcription regulatory networks in Caenorhabditis elegans

Gene

Public Gene Name

wrk-1  

Sequence Name

F41D9.3  

WB ID

WBGene00006942  

Description

wrk-1 encodes, by alternative splicing, at least three isoforms of a GPI-anchored immunoglobulin superfamily (IgSF) protein orthologous to Drosophila KLINGON, WRAPPER, CG7166, and CG13506; WRK-1 is expressed in the pioneering embryonic motoneurons (eMNs) DA, DB, and DD; WRK-1 expression in DA, DB, and DD is necessary and sufficient to prevent follower axons from inappropriately crossing the ventral midline; WRK-1 also retards developmental changes in the outward current of maturing AIY interneurons; in addition to eMNs and AIY neurons, WRK-1 is expressed in ASI and SMDV/D neurons, along with sheath and socket cells, intestine, the excretory gland cell, distal tip cells, and coelomocytes; wrk-1 transcription in AIY requires TTX-3, being greatly reduced in a ttx-3(ot22) mutant background; however, wrk-1 may not be transcriptionally activated by CEH-10/TTX-3 heterodimers, since wrk-1 lacks an AIY motif in its cis-regulatory sequences; WRK-1 binds VAB-1 or VAB-2 in vitro, and wrk-1(ok695) mutations fail to enhance vab-1 or a triple vab-2, efn-2, and efn-3 mutation, indicating that WRK-1 acts in concert with ephrins; wrk-1(ok695) null mutants exhibit midline crossover defects in the axons of HSN, PVQ, AV-type, and PVC neurons; wrk-1(ok695) and wrk-1(tm1099) mutant neurons have normal whole cell capacitance but precociously altered their outward current from a slowly activating, sustained current to a rapidly-activating one; hypodermal misexpression of WRK-1 induces defects in PVQ axonal outgrowth, which are enhanced by a wrk-1(ok695) mutant background; wrk-1(ok695) mutations enhance sax-3(ky123), indicating that WRK-1 and SAX-3 act in parallel.