Endoplasmic reticulum membrane {Experimental EvidencePubMed:22542100}; Single-pass type IV membrane protein {Experimental EvidencePubMed:22542100}. Nucleus envelope {Experimental EvidencePubMed:22542100}. Cytoplasm, cytoskeleton, microtubule organizing center, centrosome {Experimental EvidencePubMed:22542100}. Cytoplasm, cytoskeleton, spindle pole {Experimental EvidencePubMed:22542100}. Chromosome {Experimental EvidencePubMed:22542100}. Note=Localized at both male and female pronuclear membranes during pronuclear congression and fusion. Colocalized with tubulin at the centrosome adjacent to the nuclear membrane. At prophase is localized at the centrosome on opposite sides of the zygotic nucleus and at the reforming nuclear membrane. At metaphase is juxtaposed with the centrosomes at the mitotic spindle poles. During chromosome segregation is localized with the chromatin. Undetectable at the centrosome at the onset of anaphase, but becomes again apparent by late mitosis.
The nuclear envelope is a membrane system which surrounds the nucleoplasm of eukaryotic cells. It is composed of the nuclear lamina, nuclear pore complexes and two nuclear membranes. The space between the two membranes is called the nuclear intermembrane space.
A maternally expressed membrane and cytoskeletal linker protein, which is essential for attachment of the centrosome to the male pronucleus. Promotes male and female pronucleus congression and subsequent fusion after fertilization. Congression is mediated by the sperm aster microtubules. {Experimental EvidencePubMed:12874114, Experimental EvidencePubMed:22542100}.
Note=Defects in irag2 are a cause of pronuclear congression/fusion and chromosomal segregation abnormalities in the zygote named futile cycle (fue), a lethal recessive maternal-effect mutant. Mutant embryos undergo several cycles of anucleate cleavage and die. {Experimental EvidencePubMed:12874114}.
National and Kapodistrian University of Athens
Department of Biology
Biophysics & Bioinformatics Laboratory