Lanz Alexander J, Walker Alexandra K, Jamshad Mohammed, Garvin Alexander J, Stewart Matthew, Wotherspoon Peter, Cooper Benjamin F, Mackintosh Matthew, Crutchley Oliver, Knowles Timothy J, Morris Joanna R
Birmingham Centre for Genome Biology and Department of Cancer and Genomic Sciences, School of Medical Sciences, College of Medicine and Health, University of Birmingham, Birmingham, B15 2TT, UK.
SUMO Biology Lab, School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
EMBO J. 2025 Aug 20. doi: 10.1038/s44318-025-00532-y.
Mammalian cells express three conjugatable SUMO variants: SUMO1 and the closely related SUMO2 and SUMO3 (together referred to as SUMO2/3). While some substrates are modified by both, others show a clear preference, though the basis for this selectivity remains unclear. Here, we examine a modification of the catalytic component of the human SUMO activation enzyme, SAE2. We find that lysine 164 of SAE2 undergoes HDAC6-dependent deacetylation during mitosis. A non-deacetylatable acetyl-mimetic mutant, SAE2-K164Q, selectively enhances SUMO2 over SUMO1 activation and conjugation, and distinguishes between SUMO1 and SUMO2/3 based on differences in their C-terminal tails. Complementation of SAE2-deficient or inhibited cells with SAE2-K164Q suppresses mitotic SUMO1 conjugation and promotes multipolar spindle formation. We identify NuMA as a SUMO E1-dependent substrate and demonstrate that mitotic defects caused by SAE2-K164Q or HDAC6 inhibition are rescued by SUMO1 overexpression or expression of a GFP-SUMO1-NuMA-K1766R fusion. These results support a model in which SAE1:SAE2 deacetylation during early mitosis promotes SUMO1 conjugation to ensure mitotic fidelity, highlighting a regulatory role for the SUMO-activating enzyme in the selection of SUMO proteins.
哺乳动物细胞表达三种可共价连接的SUMO变体：SUMO1以及与之密切相关的SUMO2和SUMO3（统称为SUMO2/3）。虽然有些底物会被两者修饰，但其他底物则表现出明显的偏好，不过这种选择性的基础尚不清楚。在这里，我们研究了人类SUMO激活酶SAE2的催化成分的一种修饰。我们发现SAE2的赖氨酸164在有丝分裂期间经历了依赖HDAC6的去乙酰化。一种不可去乙酰化的乙酰模拟突变体SAE2-K164Q，选择性地增强了SUMO2而非SUMO1的激活和共价连接，并根据SUMO1和SUMO2/3 C末端尾巴的差异来区分它们。用SAE2-K164Q对SAE2缺陷或受抑制的细胞进行互补，可抑制有丝分裂期间的SUMO1共价连接并促进多极纺锤体形成。我们将NuMA鉴定为一种依赖SUMO E1的底物，并证明SAE2-K164Q或HDAC6抑制引起的有丝分裂缺陷可通过SUMO1过表达或GFP-SUMO1-NuMA-K1766R融合蛋白的表达来挽救。这些结果支持了一个模型，即在有丝分裂早期SAE1:SAE2的去乙酰化促进SUMO1共价连接以确保有丝分裂的保真度，突出了SUMO激活酶在SUMO蛋白选择中的调节作用。
