Journal article
Presence of Inositol 1,4,5-Trisphosphate Receptor, Calreticulin, and Calsequestrin in Eggs of Sea Urchins and Xenopus laevis
Developmental biology, Vol.161(2), pp.466-476
1994
DOI: 10.1006/dbio.1994.1045
PMID: 8313995
Abstract
The presence of inositol 1,4,5-trisphosphate receptor (InsP
3R), calreticulin, and calsequestrin was demonstrated in eggs of sea urchins (
Lytechinus pictus, Lytechinus variegatus, and
Strongylocentroutus purpuratus) and
Xenopus laevis. Binding of inositol 1,4,5-trisphosphate (InsP
3) to microsomes of
L. pictus eggs was inhibited by heparin and NaCl. An affinity-purified antibody against the C-terminal of the type I InsP
3R, which recognizes InsP
3R isoforms of rabbit brain (273 kDa) and
Xenopus oocytes and eggs (256 kDa), reacted with a 373-kDa protein in sea urchin eggs. The 373-kDa protein was tentatively identified as the sea urchin egg InsP
3R. Observations with fluorescence microscopy indicated that the InsP
3R is present throughout the cytoplasm of sea urchin eggs in a pattern consistent with the distribution of endoplasmic reticulum. Small differences in the relative amount of reaction deposits in cortex vs subcortex were noted among the species of sea urchins examined. Reaction product was also localized to the periphery of female pronuclei in eggs of all three sea urchins. InsP
3R reactivity was present in the perinuclear region, along the periphery of the germinal vesicle, and throughout the animal and vegetal hemispheres of
Xenopus oocytes. A similar cytoplasmic staining pattern was also observed in eggs, although islands of reactivity, much larger than those in oocytes, were present in the animal hemisphere of eggs. Calreticulin and calsequestrin in sea urchin eggs had the same molecular mass as in rabbit brain (56 and 60 kDa, respectively), but differed from those present in
Xenopus oocytes/eggs (61 and 57 kDa, respectively). The distribution of calreticulin and calsequestrin in both sea urchin and
Xenopus oocytes and eggs was similar to that observed for the InsP
3R. These results are discussed in relation to previous studies of Ca
2+ regulation during egg development and fertilization and suggest that in the oocytes and eggs of the species examined, InsP
3-sensitive Ca
2+ stores play an important role in the regulation of cellular Ca
2+.
Details
- Title: Subtitle
- Presence of Inositol 1,4,5-Trisphosphate Receptor, Calreticulin, and Calsequestrin in Eggs of Sea Urchins and Xenopus laevis
- Creators
- Jan B ParysSandra M McPhersonLori MathewsKevin P CampbellFrank J Longo
- Resource Type
- Journal article
- Publication Details
- Developmental biology, Vol.161(2), pp.466-476
- Publisher
- Elsevier Inc
- DOI
- 10.1006/dbio.1994.1045
- PMID
- 8313995
- ISSN
- 0012-1606
- eISSN
- 1095-564X
- Language
- English
- Date published
- 1994
- Academic Unit
- Neurology; Molecular Physiology and Biophysics; Anatomy and Cell Biology; Iowa Neuroscience Institute
- Record Identifier
- 9984020866502771
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