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.
| Original language | English |
|---|---|
| Pages (from-to) | 146-153 |
| Number of pages | 8 |
| Journal | Journal of Structural Biology |
| Volume | 137 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - 2002 |
Bibliographical note
Funding Information:We thank Kenny Lee and Kathy Wilson for the Ce-emerin and Ce-MAN1 cDNA constructs and for sharing the two anti-lamin antibodies. We also thank Klaus Weber for the bacterially purified Ce-lamin. We also thank Kathy Wilson for critical reading of the manuscript. This work was supported by grants from the USA-Israel Binational Science Foundation (BSF), the Israel Science Foundation (ISF), and the German-Israel Foundation (GIF 1-573-036.13) (to Y.G.). B.M.H. was supported by a predoctoral fellowship (Howard Hughes Medical institute). H.R.H. is an Investigator of the Howard Hughes Medical Institute.
Keywords
- Apoptosis
- C. elegans
- Emerin
- Lamin
- MAN1
- Nuclear envelope
- Programmed cell death