Association of prenylated proteins with the plasma membrane and the inner nuclear membrane is mediated by the same membrane-targeting motifs.

ABSTRACT: Targeting of nuclear lamins to the inner nuclear envelope membrane requires a nuclear localization signal and CaaX motif-dependent posttranslational modifications, including isoprenylation and carboxyl methylation. These modifications, although necessary for membrane targeting, are not sufficient to mediate stable association with membranes. We show that two variants of lamin B3 (i.e., B3a and B3b) exist in Xenopus oocytes. They are encoded by two alternatively spliced, developmentally regulated mRNAs. The two lamin variants differ greatly in their membrane association in meiotically matured eggs. The presence of an extra cysteine residue (as a potential palmitoylation site) and a basic cluster in conjunction with the CaaX motif function as secondary targeting signals responsible for the s

SUBMITTER: Hofemeister H 

PROVIDER: S-EPMC14988 | biostudies-literature | 2000 Sep

REPOSITORIES: biostudies-literature