EGG-3 regulates cell-surface and cortex rearrangements during egg activation in Caenorhabditis elegans.
Fertilization triggers egg activation and converts the egg into a developing embryo. The events of this egg-to-embryo transition typically include the resumption of meiosis, the reorganization of the cortical actin cytoskeleton, and the remodeling of the oocyte surface. The factors that regulate sperm-dependent egg-activation events are not well understood. Caenorhabditis elegans EGG-3, a member of the protein tyrosine phosphatase-like (PTPL) family, is essential for regulating cell-surface and cortex rearrangements during egg activation in response to sperm entry. Although fertilization occurred normally in egg-3 mutants, the polarized dispersal of F-actin is altered, a chitin eggshell is not formed, and no polar bodies are produced. EGG-3 is associated with the oocyte plasma membrane in a pattern that is similar to CHS-1 and MBK-2. CHS-1 is required for eggshell deposition, whereas MBK-2 is required for the degradation of maternal proteins during the egg-to-embryo transition. The localization of CHS-1 and EGG-3 are interdependent and both genes were required for the proper localization of MBK-2 in oocytes. Therefore, EGG-3 plays a central role in egg activation by influencing polarized F-actin dynamics and the localization or activity of molecules that are directly involved in executing the egg-to-embryo transition.
Maruyama
Rika
R
Waksman Institute, Department of Genetics, Rutgers University, Piscataway, New Jersey 08854, USA.
Velarde
Nathalie V
NV
Klancer
Richard
R
Gordon
Scott
S
Kadandale
Pavan
P
Parry
Jean M
JM
Hang
Julie S
JS
Rubin
Jacob
J
Stewart-Michaelis
Allison
A
Schweinsberg
Peter
P
Grant
Barth D
BD
Piano
Fabio
F
Sugimoto
Asako
A
Singson
Andrew
A
D000199:Actins / Q000032:analysis / Q000378:metabolism; D020816:Amino Acid Motifs; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D005306:Fertilization; D049452:Green Fluorescent Proteins / Q000032:analysis; D008969:Molecular Sequence Data; D010063:Ovum / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000032:analysis / Q000378:metabolism
D000199:Actins; D029742:Caenorhabditis elegans Proteins; D049452:Green Fluorescent Proteins; C478059:MBK-2 protein, C elegans; D011505:Protein-Tyrosine Kinases; C525138:EGG-3 protein, C elegans; D017027:Protein Tyrosine Phosphatases