CNR-National Research Council of Italy, Institute of Molecular Genetics, Unit of Bologna-IOR, Bologna, Italy.
Cell Cycle. 2012 Oct 1;11(19):3568-77. doi: 10.4161/cc.21869. Epub 2012 Aug 30.
Prelamin A processing impairment is a common feature of a restricted group of rare genetic alterations/disorders associated with a wide range of clinical phenotypes. Changes in histone posttranslational modifications, alterations in non-histone chromatin proteins and chromatin disorganization have been specifically linked to impairment of specific, distinct prelamin A processing steps, but the molecular mechanism involved in these processes is not yet understood . In this study, we show that the accumulation of wild-type prelamin A detected in restrictive dermopathy (RD), as well as the accumulation of mutated forms of prelamin A identified in familial partial lipodystrophy (FPLD) and mandibuloacral dysplasia (MADA), affect the nuclear localization of barrier-to-autointegration factor (BAF), a protein able to link lamin A precursor to chromatin remodeling functions. Our findings, in accordance with previously described results, support the hypothesis of a prelamin A involvement in BAF nuclear recruitment and suggest BAF-prelamin A complex as a protein platform usually activated in prelamin A-accumulating diseases. Finally, we demonstrate the involvement of the inner nuclear membrane protein emerin in the proper localization of BAF-prelamin A complex.
早老素 A 加工障碍是一组与广泛的临床表型相关的罕见遗传改变/疾病的共同特征。组蛋白翻译后修饰的改变、非组蛋白染色质蛋白的改变和染色质紊乱与特定的、不同的早老素 A 加工步骤的损伤特别相关,但涉及这些过程的分子机制尚不清楚。在这项研究中,我们表明,在限制型皮肤营养不良(RD)中检测到的野生型早老素 A 的积累,以及在家族性部分脂肪营养不良(FPLD)和下颌骨-肢端发育不良(MADA)中鉴定的突变形式的早老素 A 的积累,影响了屏障到自动整合因子(BAF)的核定位,BAF 是一种能够将 lamin A 前体与染色质重塑功能联系起来的蛋白质。我们的发现与之前描述的结果一致,支持早老素 A 参与 BAF 核募集的假说,并表明 BAF-早老素 A 复合物作为一种通常在早老素 A 积累疾病中激活的蛋白质平台。最后,我们证明了核膜内蛋白 emerin 在内核膜蛋白 emerin 在 BAF-早老素 A 复合物的正确定位中的作用。