Schrader J W, Ziltener H J, Leslie K B
Proc Natl Acad Sci U S A. 1986 Apr;83(8):2458-62. doi: 10.1073/pnas.83.8.2458.
A group of cytokines characterized by a common set of target cells--namely, the pluripotential hemopoietic stem cells or their cellular derivatives--share similarities in the amino acid sequence at their N terminus or in the putative signal peptide immediately prior to the published N terminus. Murine P-cell-stimulating factor (PSF), murine and human interleukin 2 (IL-2), murine and human granulocyte-macrophage colony-stimulating factor (GM-CSF), human erythropoietin, and human interleukin 1 beta all share alanine as the N-terminal amino acid and have some similarities in the succeeding three or four amino acids. In the case of murine PSF and GM-CSF, the six N-terminal amino acids are readily cleaved from mature molecules and are lacking from the N-terminal amino acid sequences reported initially. A sixth cytokine, colony-stimulating factor 1, has an alanine followed by a similar pattern of five amino acids at the end of the putative signal peptide. GM-CSF and IL-2 have more extensive homology, about 25% of residues being identical in three regions that comprise about 70% of the molecules. Only minor similarities of uncertain significance were found among the complete amino acid sequences of the other cytokines. Although its evolutionary origin is uncertain, the homology around the N terminus may provide a structural marker for a group of cytokines active on the pluripotential hemopoietic stem cell and its derivatives.
一组细胞因子，其特征在于具有一组共同的靶细胞，即多能造血干细胞或其细胞衍生物，它们在N端的氨基酸序列或在已发表的N端之前的假定信号肽中具有相似性。小鼠P细胞刺激因子（PSF）、小鼠和人白细胞介素2（IL-2）、小鼠和人粒细胞-巨噬细胞集落刺激因子（GM-CSF）、人促红细胞生成素和人白细胞介素1β均以丙氨酸作为N端氨基酸，并且在随后的三到四个氨基酸中具有一些相似性。就小鼠PSF和GM-CSF而言，六个N端氨基酸很容易从成熟分子中切割下来，最初报道的N端氨基酸序列中没有这些氨基酸。第六种细胞因子集落刺激因子1，在假定信号肽的末端有一个丙氨酸，后面跟着一个相似的五个氨基酸的模式。GM-CSF和IL-2具有更广泛的同源性，在构成分子约70%的三个区域中，约25%的残基是相同的。在其他细胞因子的完整氨基酸序列中，仅发现了一些意义不确定的微小相似性。尽管其进化起源尚不确定，但N端周围的同源性可能为一组对多能造血干细胞及其衍生物有活性的细胞因子提供一个结构标记。
