Roles of LAP2 proteins in nuclear assembly and DNA replication: truncated LAP2beta proteins alter lamina assembly, envelope formation, nuclear size, and DNA replication efficiency in Xenopus laevis extracts.

ABSTRACT: Humans express three major splicing isoforms of LAP2, a lamin- and chromatin-binding nuclear protein. LAP2beta and gamma are integral membrane proteins, whereas alpha is intranuclear. When truncated recombinant human LAP2beta proteins were added to cell-free Xenopus laevis nuclear assembly reactions at high concentrations, a domain common to all LAP2 isoforms (residues 1-187) inhibited membrane binding to chromatin, whereas the chromatin- and lamin-binding region (residues 1-408) inhibited chromatin expansion. At lower concentrations of the common domain, membranes attached to chromatin with a unique scalloped morphology, but these nuclei neither accumulated lamins nor replicated. At lower concentrations of the chromatin- and lamin-binding region, nuclear envelopes and lamins assembled, bu

SUBMITTER: Gant TM 

PROVIDER: S-EPMC2150574 | biostudies-literature | 1999 Mar

REPOSITORIES: biostudies-literature