We have previously shown that Xenopus oocytes, eggs, and early embryos contain lamins LII and LIII, and that portions of each are associated with distinct egg vesicle populations. We now report that a lamin similar or identical to the B-type lamin LI is also present in oocyte nuclei and in egg extracts. We have quantitated the three B-type lamins per oocyte nucleus, and have calculated relative...

A cDNA clone encoding a portion of Drosophila nuclear lamins Dm1 and Dm2 has been identified by screening a lambda-gt11 cDNA expression library using Drosophila lamin-specific monoclonal antibodies. Two different developmentally regulated mRNA species were identified by Northern blot analysis using the initial cDNA as a probe, and full-length cDNA clones, apparently corresponding to each messag...

This study was aimed at elucidating the fate of three important nuclear envelope components - lamins B and A/C and nucleoporin Nup160, during meiotic maturation of mouse oocytes. These proteins were localized by epifluorescence and confocal microscopy using specific antibodies in oocytes at different stages from prophase I (germinal vesicle) to metaphase II. In immature germinal vesicle oocytes...

Hematopoietic stem and progenitor cells, as well as nucleated erythroblasts and megakaryocytes, reside preferentially in adult marrow microenvironments whereas other blood cells readily cross the endothelial barrier into the circulation. Because the nucleus is the largest organelle in blood cells, we hypothesized that (i) cell sorting across microporous barriers is regulated by nuclear deformab...

A-type lamins A and C are nuclear intermediate filament proteins in which mutations have been implicated in multiple disease phenotypes commonly known as laminopathies. A few studies have implicated sumoylation in the regulation of A-type lamins. Sumoylation is a post-translational protein modification that regulates a wide range of cellular processes through the attachment of small ubiquitin-r...

Sad1/UNC84 (SUN) domain proteins are a highly conserved family of inner nuclear membrane localised proteins in eukaryotes. One of their main functions is as key components of nucleo-cytoskeletal bridging complexes, in which SUN proteins associate with nucleoskeletal elements. In metazoans these are the lamins, which form a supportive structural network termed the lamina. Plants lack sequence ho...

Self-digestion of cytoplasmic components is the hallmark of autophagic programmed cell death. This auto-degradation appears to be distinct from what occurs in apoptotic cells that are engulfed and digested by phagocytes. Although much is known about apoptosis, far less is known about the mechanisms that regulate autophagic cell death. Here we show that autophagic cell death is regulated by ster...