Giancotti V, Bandiera A, Ciani L, Santoro D, Crane-Robinson C, Goodwin G H, Boiocchi M, Dolcetti R, Casetta B
Dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole, Università di Trieste, Italy.
Eur J Biochem. 1993 Apr 15;213(2):825-32. doi: 10.1111/j.1432-1033.1993.tb17825.x.
Exhaustive extraction of mouse tissues with perchloric acid has been used together with reverse-phase HPLC and electrophoresis to quantify the amounts of chromosomal proteins HMG17, HMG14 and HMGI, relative to histone H1. Normal lung and thymus contain approximately 3% HMG17/HMG14 but only approximately 2% HMGI. In tumor tissues (Lewis lung carcinoma and lymphoma NQ35), the amount of HMG17/HMG14 is not greatly altered but HMGI levels rise considerably, reaching 10% in Lewis lung carcinoma. HMGI synthesis does not replace HMG17/HMG14 proteins, suggesting that HMGI proteins contribute to the structure of chromatin regions in a manner distinct from those of HMG17/HMG14. Ion-spray mass spectrometry has been used to determine the molecular masses of H1 subtypes from the same four mouse tissues. In addition to the six known species H1 zero, H1a, H1b, H1c, H1d and H1e, a newly defined subtype of mass 21,756 Da from Lewis lung carcinoma, named H1L was identified. Several phosphorylated H1 subtypes have also been defined by mass spectrometry. The combined use of reverse-phase HPLC and electrophoresis permitted quantification of these seven histone H1 subtypes in the four mouse tissues. Increased phosphorylation of H1 subtypes in tumors parallels the phosphorylation of HMGI proteins which are present in great amounts, showing that both are involved as post-translational-modified forms in the structure of the chromatin of neoplastic systems.
用高氯酸对小鼠组织进行彻底提取，再结合反相高效液相色谱法和电泳法，以相对于组蛋白H1来定量染色体蛋白HMG17、HMG14和HMGI的含量。正常肺和胸腺中HMG17/HMG14约占3%，但HMGI仅约占2%。在肿瘤组织（Lewis肺癌和淋巴瘤NQ35）中，HMG17/HMG14的含量变化不大，但HMGI水平显著升高，在Lewis肺癌中达到10%。HMGI的合成并未取代HMG17/HMG14蛋白，这表明HMGI蛋白以一种不同于HMG17/HMG14的方式对染色质区域结构起作用。离子喷雾质谱法已用于测定来自相同四种小鼠组织的H1亚型的分子量。除了六种已知的H1零、H1a、H1b、H1c、H1d和H1e亚型外，还从Lewis肺癌中鉴定出一种新定义的分子量为21,756 Da的亚型，命名为H1L。通过质谱法还确定了几种磷酸化的H1亚型。反相高效液相色谱法和电泳法的联合使用能够对这四种小鼠组织中的七种组蛋白H1亚型进行定量。肿瘤中H1亚型磷酸化的增加与大量存在的HMGI蛋白的磷酸化情况相似，表明二者都作为翻译后修饰形式参与肿瘤系统染色质的结构组成。
