Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77550, USA.
Mol Cell. 2024 Aug 8;84(15):2900-2917.e10. doi: 10.1016/j.molcel.2024.06.017. Epub 2024 Jul 19.
INTS11 and CPSF73 are metal-dependent endonucleases for Integrator and pre-mRNA 3'-end processing, respectively. Here, we show that the INTS11 binding partner BRAT1/CG7044, a factor important for neuronal fitness, stabilizes INTS11 in the cytoplasm and is required for Integrator function in the nucleus. Loss of BRAT1 in neural organoids leads to transcriptomic disruption and precocious expression of neurogenesis-driving transcription factors. The structures of the human INTS9-INTS11-BRAT1 and Drosophila dIntS11-CG7044 complexes reveal that the conserved C terminus of BRAT1/CG7044 is captured in the active site of INTS11, with a cysteine residue directly coordinating the metal ions. Inspired by these observations, we find that UBE3D is a binding partner for CPSF73, and UBE3D likely also uses a conserved cysteine residue to directly coordinate the active site metal ions. Our studies have revealed binding partners for INTS11 and CPSF73 that behave like cytoplasmic chaperones with a conserved impact on the nuclear functions of these enzymes.
INTS11 和 CPSF73 分别是整合酶和前体 mRNA 3'端加工的金属依赖性核酸内切酶。在这里，我们表明 INTS11 的结合伴侣 BRAT1/CG7044 是神经元适应性的重要因素，它在细胞质中稳定 INTS11，并在核内维持整合酶的功能。神经类器官中 BRAT1 的缺失导致转录组的破坏和神经发生驱动转录因子的过早表达。人 INTS9-INTS11-BRAT1 和果蝇 dIntS11-CG7044 复合物的结构表明，BRAT1/CG7044 的保守 C 末端被捕获在 INTS11 的活性位点中，其中一个半胱氨酸残基直接配位金属离子。受这些观察结果的启发，我们发现 UBE3D 是 CPSF73 的结合伴侣，UBE3D 可能也使用保守的半胱氨酸残基直接配位活性位点的金属离子。我们的研究揭示了 INTS11 和 CPSF73 的结合伴侣，它们的行为类似于细胞质伴侣，对这些酶的核功能具有保守影响。
