An extracellular matrix damage sensor signals through membrane-associated kinase DRL-1 to mediate cytoprotective responses inCaenorhabditis elegans

Abstract

We and others previously identified circumferential bands of collagen named annular furrows as key components of a damage sensor in the cuticle of Caenorhabditis elegans that regulates cytoprotective genes. Mutation or loss of non-collagen secreted proteins OSM-7, OSM-8, and OSM-11 activate the same cytoprotective responses without obvious changes to the cuticle indicating that other extracellular proteins are involved. Here, we used RNAi screening to identify protein kinase DRL-1 as a key modulator of cytoprotective gene expression and stress resistance in furrow and extracellular OSM protein mutants. DRL-1 functions downstream from furrow disruption and is expressed in cells that induce cytoprotective genes. DRL-1 is not required for expression of cytoprotective genes under basal or oxidative stress conditions consistent with specificity to extracellular signals. DRL-1 was previously shown to regulate longevity via a ‘Dietary Restriction-Like’ state, but it functions downstream from furrow disruption by a distinct mechanism. The kinase domain of DRL-1 is related to mammalian MEKK3, and MEKK3 is recruited to a plasma membrane osmosensor complex by a scaffold protein. In C. elegans, DRL-1 contains an atypical hydrophobic C-terminus with predicted transmembrane domains and is constitutively expressed at or near the plasma membrane where it could function to receive extracellular damage signals for cells that mount cytoprotective responses.

Follicle stimulating hormone signaling opposes the DRL-1/FLR-4 MAP Kinases to balance p38-mediated growth and lipid homeostasis inC. elegans

“…Although these proteins are expressed at low levels, we detected the mGL::FLR-4 and mKate2::DRL-1 proteins at the intestinal plasma membrane (Fig. 3D), consistent with over-expression studies of FLR-4 and DRL-1 (Kobayashi et al 2011; Wimberly and Choe 2022). Furthermore, reciprocal co-immunoprecipitation studies demonstrated that HA::FLR-4 and FLAG::DRL-1 interact (Fig.…”

Extracellular matrix regulation of stress response genes during larval development in Caenorhabditis elegans

“…Loss or mutation of any one of 6collagen encoding genes ( dpy-2 , 3 , 7 , 8 , 9 , and 10) disrupts furrows and activates stress responses ( Dodd et al 2018 ); DPY-7 and DPY-10 antibodies and DPY-7::GFP fusion protein localize to furrows ( McMahon et al 2003 ; Miao et al 2020 ). These results and subsequent genetic studies are consistent with a furrow-associated damage sensor that regulates 3 conserved environmental stress responses via distinct, but overlapping, downstream signaling ( Dodd et al 2018 ; Wimberly and Choe 2022 ).…”

“…Caenorhabditis elegans develops through 5 stages delineated by synthesis and molting of cuticles ( Cox and Hirsh 1985 ; Johnstone 2000 ). Roles of furrow collagens in stress response regulation have only been studied in the terminal adult stage ( Dodd et al 2018 ; Wimberly and Choe 2022 ). The cuticle functions as a flexible collagenous barrier and exoskeleton in all stages, but there are differences that could influence environmental stress sensing.…”

Sexual dimorphism in Caenorhabditis elegans stress resistance

“…Given difficulties interpreting basal mRNA differences and lack of correlation between stress response induction levels and male-biased stress resistance, we next used fluorescent transcriptional reporters for canonical osmotic, heat shock, and detoxification stress response genes ( gpdh-1p :: dsRed2 , hsp-16 . 2p :: GFP , and gst-4p :: GFP , respectively) [ 46 , 71 , 72 ] to determine if there were any major differences in distributions that may correlate with stress resistance. As shown in S3A and S4 Figs, fluorescence for these reporters was not clearly visible above background in either sex under basal conditions.…”