CRT-1/calreticulin and the E3 ligase EEL-1/HUWE1 control hemidesmosome maturation in C. elegans development.
Hemidesmosomes connect the extracellular matrix (ECM) to intermediate filaments through ECM receptors and plakins (plectin and BPAG1e). They affect tissue integrity, wound healing, and carcinoma invasion. Although biochemical and time-lapse studies indicate that alpha6beta4-integrin (ECM receptor) and plectin play a central role in modulating hemidesmosome disassembly, the mechanisms controlling hemidesmosome biogenesis in vivo remain poorly understood. The nematode C. elegans provides a powerful genetic model to address this issue. We performed a genome-wide RNA interference screen in C. elegans, searching for genes that decrease the viability of a weak VAB-10A/plakin mutant. We identified 14 genes that have human homologs with predicted roles in different cellular processes. We further characterized two genes encoding the chaperone CRT-1/calreticulin and the HECT domain E3 ubiquitin ligase EEL-1/HUWE1. CRT-1 controls by as little as 2-fold the abundance of UNC-52/perlecan, an essential hemidesmosome ECM ligand. Likewise, EEL-1 fine tunes by 2-fold the abundance of myotactin, the putative hemidesmosome ECM receptor. CRT-1 and EEL-1 activities, and by extension other genes identified in our screen, are essential during embryonic development to enable hemidesmosomes exposed to mechanical tension to mature into a tension-resistant form. Our findings should help understand how hemidesmosome dynamics are regulated in vertebrate systems.
Department of Cell Biology and Development, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, 1 rue Laurent Fries, BP 10142, 67400 Illkirch, France.
Hala
H
Zahreddine
Huimin
H
Zhang
Marie
M
Diogon
Yasuko
Y
Nagamatsu
Michel
M
Labouesse
D000818:Animals; D015153:Blotting, Western; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D037282:Calreticulin / Q000235:genetics / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D020043:Genes, Essential / Q000235:genetics; D022002:Hemidesmosomes / Q000378:metabolism*; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism; D008954:Models, Biological; D009124:Muscle Proteins / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D051179:Plakins / Q000378:metabolism; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; D037282:Calreticulin; D019812:Heparan Sulfate Proteoglycans; D009124:Muscle Proteins; D051179:Plakins; C120778:let-805 protein, C elegans; C071927:perlecan; C521393:EEL-1 protein, C elegans; D044767:Ubiquitin-Protein Ligases