TY - JOUR
T1 - C. elegans NIMA-related kinases NEKL-2 and NEKL-3 are required for the completion of molting
AU - Yochem, John
AU - Lažetić, Vladimir
AU - Bell, Leslie
AU - Chen, Lihsia
AU - Fay, David
N1 - Publisher Copyright:
© 2014 Elsevier Inc.
PY - 2015/2/15
Y1 - 2015/2/15
N2 - Caenorhabditis elegans molting is a process during which the apical extracellular matrix of the epidermis, the cuticle, is remodeled through a process of degradation and re-synthesis. Using a genetic approach, we identified nekl-3 as essential for the completion of molting. NEKL-3 is highly similar to the mammalian NEK kinase family members NEK6 and NEK7. Animals homozygous for a hypomorphic mutation in nekl-3, sv3, had a novel molting defect in which the central body region, but not the head or tail, was unable to shed the old cuticle. In contrast, a null mutation in nekl-3, gk506, led to complete enclosure within the old cuticle. nekl-2, which is most similar to mammalian NEK8, was also essential for molting. Mosaic analyses demonstrated that NEKL-2 and NEKL-3 were specifically required within the large epidermal syncytium, hyp7, to facilitate molting. Consistent with this, NEKL-2 and NEKL-3 were expressed at the apical surface of hyp7 where they localized to small spheres or tubular structures. Inhibition of nekl-2, but not nekl-3, led to the mislocalization of LRP-1/megalin, a cell surface receptor for low-density lipoprotein (LDL)-binding proteins. In addition, nekl-2 inhibition led to the mislocalization of several other endosome-associated proteins. Notably, LRP-1 acts within hyp7 to facilitate completion of molting, suggesting at least one mechanism by which NEKL-2 may influence molting. Notably, our studies failed to reveal a requirement for NEKL-2 or NEKL-3 in cell division, a function reported for several mammalian NEKs including NEK6 and NEK7. Our findings provide the first genetic and in vivo evidence for a role of NEK family members in endocytosis, which may be evolutionarily conserved.
AB - Caenorhabditis elegans molting is a process during which the apical extracellular matrix of the epidermis, the cuticle, is remodeled through a process of degradation and re-synthesis. Using a genetic approach, we identified nekl-3 as essential for the completion of molting. NEKL-3 is highly similar to the mammalian NEK kinase family members NEK6 and NEK7. Animals homozygous for a hypomorphic mutation in nekl-3, sv3, had a novel molting defect in which the central body region, but not the head or tail, was unable to shed the old cuticle. In contrast, a null mutation in nekl-3, gk506, led to complete enclosure within the old cuticle. nekl-2, which is most similar to mammalian NEK8, was also essential for molting. Mosaic analyses demonstrated that NEKL-2 and NEKL-3 were specifically required within the large epidermal syncytium, hyp7, to facilitate molting. Consistent with this, NEKL-2 and NEKL-3 were expressed at the apical surface of hyp7 where they localized to small spheres or tubular structures. Inhibition of nekl-2, but not nekl-3, led to the mislocalization of LRP-1/megalin, a cell surface receptor for low-density lipoprotein (LDL)-binding proteins. In addition, nekl-2 inhibition led to the mislocalization of several other endosome-associated proteins. Notably, LRP-1 acts within hyp7 to facilitate completion of molting, suggesting at least one mechanism by which NEKL-2 may influence molting. Notably, our studies failed to reveal a requirement for NEKL-2 or NEKL-3 in cell division, a function reported for several mammalian NEKs including NEK6 and NEK7. Our findings provide the first genetic and in vivo evidence for a role of NEK family members in endocytosis, which may be evolutionarily conserved.
KW - C. elegans
KW - Endocytosis
KW - Hyp7
KW - Kinases
KW - Molting
KW - NEK
KW - NEKL-2
KW - NEKL-3
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UR - http://www.scopus.com/inward/citedby.url?scp=84922724599&partnerID=8YFLogxK
U2 - 10.1016/j.ydbio.2014.12.008
DO - 10.1016/j.ydbio.2014.12.008
M3 - Article
C2 - 25523392
AN - SCOPUS:84922724599
SN - 0012-1606
VL - 398
SP - 255
EP - 266
JO - Developmental Biology
JF - Developmental Biology
IS - 2
ER -