TARGETING OF MEMBRANES TO SEA-URCHIN SPERM CHROMATIN IS MEDIATED BY ALAMIN-B RECEPTOR-LIKE INTEGRAL MEMBRANE-PROTEIN

Citation
P. Collas et al., TARGETING OF MEMBRANES TO SEA-URCHIN SPERM CHROMATIN IS MEDIATED BY ALAMIN-B RECEPTOR-LIKE INTEGRAL MEMBRANE-PROTEIN, The Journal of cell biology, 135(6), 1996, pp. 1715-1725
Citations number
49
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell Biology
Journal title
ISSN journal
0021-9525
Volume
135
Issue
6
Year of publication
1996
Part
2
Pages
1715 - 1725
Database
ISI
SICI code
0021-9525(1996)135:6<1715:TOMTSS>2.0.ZU;2-N
Abstract
We have identified an integral membrane protein of sea urchin gametes with an apparent molecular mass of 56 kD that cross-reacts with an ant ibody against the nucleoplasmic NH2-terminal domain of human lamin B r eceptor (LBR). In mature sperm, p56 is located at the tip and base of the nucleus from where it is removed by egg cytosol in vitro. In the e gg, p56 is present in a subset of cytoplasmic membranes (MV2 beta) whi ch contributes the bulk of the nuclear envelope during male pronuclear formation. p56-containing vesicles are required for nuclear envelope assembly and have a chromatin-binding capacity that is mediated by p56 . Lamin B is not present in these vesicles and is imported into the nu cleus from a soluble pool at a later stage of pronuclear formation, La min B incorporation and addition of new membranes are necessary for pr onuclear swelling and nuclear envelope growth, We suggest that p56 is a sea urchin LBR homologue that targets membranes to chromatin and lat er anchors the membrane to the lamina.