Journal of Cell Science 115, e1406-e1406 (2002)
© 2002 The Company of Biologists Limited
A cytoskeletal histone
Histones, key components of eukaryotic chromatin, come in two types: core
histones and linker histones. Core histones are part of the nucleosome and
essential in all eukaryotes. Linker histones, by contrast, bind to the linker
DNA between nucleosomes and are dispensable in some organisms. Nonetheless
they are exclusively nuclear and function in chromatin organization —
right? Well, not exactly. Ekkehard Schulze and co-workers have identified a
novel linker histone in nematodes, H1. X, that resides in the cytoplasm (see
p. 2881). Sequence analysis
reveals that H1.X is a bona fide member of the linker histone family, but the
authors find that it predominantly localizes not to chromatin but to
tonofilaments — specialized bundles of intermediate filaments in
marginal cells of the pharynx. The protein is also present in the cytoplasm of
body-wall and vulval muscle cells. Nematodes in which Schulze and co-workers
reduced H1.X levels by RNAi exhibit uncoordinate movement and defective egg
laying. The authors therefore propose that this unusual histone has a
cytoskeletal role that is important for muscle function and development.
Related articles in JCS:
- A novel linker histone-like protein is associated with cytoplasmic filaments in Caenorhabditis elegans
- Monika A. Jedrusik, Stefan Vogt, Peter Claus, and Ekkehard Schulze
JCS 2002 115: 2881-2891.
[Abstract]
[Full Text]
