A calsequestrin-like protein in the endoplasmic reticulum of the sea urchin: localization and dynamics in the egg and first cell cycle embryo.

• DOI: 10.1083/jcb.109.1.149
• Publication Date: 2004-05-15T00:18:20Z
• Authors: J H Henson; D A Begg; S M Beaulieu; D J Fishkind; E M Bonder; M Terasaki; D Lebeche; B Kaminer
• Keywords: Calsequestrin; Organelle; Interphase

Using an antiserum produced against a purified calsequestrin-like (CSL) protein from microsomal fraction of sea urchin eggs, we performed light and electron microscopic immunocytochemical localizations on eggs embryos in the first cell cycle. The CSL has been found to bind Ca++ similarly calsequestrin, well-characterized storage sarcoplasmic reticulum muscle cells. In semi-thin frozen sections unfertilized immunofluorescent staining revealed tubuloreticular network throughout cytoplasm. Staining isolated egg cortices with showed presence submembranous polygonal, tubular similar ER patterns seen other cells treated membrane dye DiIC16[3]. during interphase cycle, cytoplasmic that was present. During mitosis, observed dramatic concentration antibody within asters mitotic apparatus where is known aggregate. Electron localization using peroxidase-labeled secondary demonstrated luminal compartment ER-like tubules. Finally, centrifugally stratified concentrated clear zone: layer highly enriched thought be site calcium release upon fertilization. This provides evidence for ability this organelle serve role regulation intracellular nonmuscle general, fertilization division particular.