Accumulation of the isolated carboxy-terminal domain of histone H1 in the Xenopus oocyte nucleus
Dingwall, C.; Allan, J.
EMBO Journal 3(9): 1933-1937
1984
ISSN/ISBN: 0261-4189 PMID: 6489317 Document Number: 231840
Histone H1 accumulates in the nucleus after injection into the cytoplasm of Xenopus oocytes. A proteolytic fragment of 89 amino acids encompassing the carboxy-terminal domain also accumulates in the nucleus. Lys, Ala and Pro compose 84% of this domain. Accumulation is not due solely to the high Lys content since poly-L-lysine does not accumulate in the nucleus when injected into the cytoplasm of Xenopus oocytes. Proteolytic fragments encompassing other domains of the molecule are degraded in the oocyte after injection. In these instances degradation is more rapid in the cytoplasm than in the nucleus giving the false impression of accumulation in the nucleus, an artefact which is likely to confuse other studies of protein migration. Susceptibility to rapid degradation is a dominant feature, thus the globular domain destabilizes the contiguous carboxy-terminal domain. The properties of the carboxy-terminal domain of H1 and the possible involvement of the amino acids Lys, Pro and Ala in migration are discussed and compared with those of a domain that specifies migration of nucleoplasmin into the oocyte nucleus.