Hsiao Susan J, Smith Susan
Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, 2nd Floor, New York, NY 10016, United States.
Biochimie. 2008 Jan;90(1):83-92. doi: 10.1016/j.biochi.2007.07.012. Epub 2007 Jul 24.
Telomeres have special needs; they require distinct mechanisms for their protection, replication, and separation at mitosis. A dedicated six-subunit protein complex termed shelterin attends to these needs. But shelterin cannot do it alone and often relies on recruits from other cellular locales. One such recruit is tankyrase 1, a poly(ADP-ribose) polymerase that is brought to telomeres by the shelterin DNA binding subunit TRF1, where it functions in telomere length regulation and sister chromatid separation. An understanding of how tankyrase 1 functions at telomeres has been confounded by its complexity; it localizes to multiple subcellular sites, it has many diverse binding partners, and it has a closely related homolog (tankyrase 2) with which it may functionally overlap. This review summarizes our current knowledge of tankyrases focusing on their localization, binding partners, and function.
端粒有特殊需求；它们在有丝分裂时需要独特的机制来保护、复制和分离。一种名为端粒保护蛋白复合体（shelterin）的由六个亚基组成的专门蛋白质复合体负责满足这些需求。但端粒保护蛋白复合体无法独自完成，它常常依赖于从细胞其他区域招募的蛋白。其中一个招募蛋白是端锚聚合酶1（tankyrase 1），它是一种聚（ADP-核糖）聚合酶，由端粒保护蛋白复合体的DNA结合亚基TRF1带到端粒，在端粒长度调节和姐妹染色单体分离中发挥作用。由于端锚聚合酶1的复杂性，人们对它在端粒上的功能的理解一直很混乱；它定位于多个亚细胞位点，有许多不同的结合伙伴，并且它有一个与之功能可能重叠的密切相关的同源物（端锚聚合酶2）。这篇综述总结了我们目前对端锚聚合酶的认识，重点关注它们的定位、结合伙伴和功能。
