CGC Bibliography Paper 5316

Fate of the nuclear lamina during Caenorhabditis elegans apoptosis.

Tzur YB, Hersh BM, Horvitz HR, Gruenbaum Y

Medline:

12064941

Citation:

Journal of Structural Biology 137: 146-153 2002

Type:

ARTICLE

Genes:

ced-3 ced-4 egl-1 unc-1

Abstract:

In vertebrates and in Drosophila, lamins and lamin-associated proteins are primary targets for cleavage by caspases. Eliminating mammalian lamins causes apoptosis, whereas expressing mutant lamins that cannot be cleaved by caspase-6 delay apoptosis. Caenorhabditis elegans has a single lamin protein, Ce-lamin, and a caspase, CED-3, that is responsible for most if not all somatic apoptosis. In this study we show that in C. elegans embryos induced to undergo apoptosis Ce-lamin is degraded surprisingly late. In such embryos CED-4 translocated to the nuclear envelope but the cytological localization of Ce-lamin remained similar to that in wild-type embryos. TUNEL labeling indicated that Ce-lamin was degraded only after DNA is fragmented. Ce-lamin, Ce-emerin, or Ce-MAN1 were not cleaved by recombinant CED-3, showing that these lamina proteins are not substrates for CED-3 cleavage. These results suggest that lamin cleavage probably is not essential for apoptosis in C. elegans.