Dingwall C, Allan J
EMBO J. 1984 Sep;3(9):1933-7. doi: 10.1002/j.1460-2075.1984.tb02072.x.
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. Lysine, alanine and proline compose 84% of this domain. Accumulation is not due solely to the high lysine 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 destabilises the contiguous carboxy-terminal domain. The properties of the carboxy-terminal domain of H1 and the possible involvement of the amino acids lysine, proline and alanine in migration are discussed and compared with those of a domain that specifies migration of nucleoplasmin into the oocyte nucleus.
组蛋白H1注射到非洲爪蟾卵母细胞的细胞质后会在细胞核中积累。一个包含羧基末端结构域的89个氨基酸的蛋白水解片段也会在细胞核中积累。赖氨酸、丙氨酸和脯氨酸构成了该结构域的84%。积累并非仅仅归因于高赖氨酸含量，因为聚-L-赖氨酸注射到非洲爪蟾卵母细胞的细胞质中时不会在细胞核中积累。注射后，包含分子其他结构域的蛋白水解片段在卵母细胞中会被降解。在这些情况下，细胞质中的降解比细胞核中更快，从而给人一种在细胞核中积累的假象，这种假象可能会混淆其他关于蛋白质迁移的研究。易快速降解是一个主要特征，因此球状结构域会使相邻的羧基末端结构域不稳定。讨论了H1羧基末端结构域的特性以及赖氨酸、脯氨酸和丙氨酸在迁移中可能的作用，并将其与指定核质蛋白迁移到卵母细胞核的结构域的特性进行了比较。
