6K5R

Complex of SUMO2 with Phosphorylated viral SIM IE2

Summary for 6K5R

• Entry DOI: 10.2210/pdb6k5r/pdb
• Descriptor: Small ubiquitin-related modifier 3, ASP-THR-ALA-GLY-CYS-ILE-VAL-ILE-SEP-ASP-SEP-GLU (2 entities in total)
• Functional Keywords: complex, protein binding-transcription complex, protein binding/transcription
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 10261.25

Authors

Chatterjee, K.S.,Das, R. (deposition date: 2019-05-30, release date: 2019-08-07, Last modification date: 2024-11-06)

Primary citation

Tripathi, V.,Chatterjee, K.S.,Das, R.
Casein kinase-2-mediated phosphorylation increases the SUMO-dependent activity of the cytomegalovirus transactivator IE2.
J.Biol.Chem., 294:14546-14561, 2019

PubMed Abstract: Many viral factors manipulate the host post-translational modification (PTM) machinery for efficient viral replication. In particular, phosphorylation and SUMOylation can distinctly regulate the activity of the human cytomegalovirus (HCMV) transactivator immediate early 2 (IE2). However, the molecular mechanism of this process is unknown. Using various structural, biochemical, and cell-based approaches, here we uncovered that IE2 exploits a cross-talk between phosphorylation and SUMOylation. A scan for small ubiquitin-like modifier (SUMO)-interacting motifs (SIMs) revealed two SIMs in IE2, and a real-time SUMOylation assay indicated that the N-terminal SIM (IE2-SIM1) enhances IE2 SUMOylation up to 4-fold. Kinetic analysis and structural studies disclosed that IE2 is a SUMO E3 ligase. We also found that two putative casein kinase 2 (CK2) sites adjacent to IE2-SIM1 are phosphorylated and in cells. The phosphorylation drastically increased IE2-SUMO affinity, IE2 SUMOylation, and E3 activity of IE2. Additional salt bridges between the phosphoserines and SUMO accounted for the increased IE2-SUMO affinity. Phosphorylation also enhanced the SUMO-dependent transactivation activity and auto-repression activity of IE2. Together, our findings highlight a novel mechanism whereby SUMOylation and phosphorylation of the viral E3 ligase and transactivator protein IE2 work in tandem to enable transcriptional regulation of viral gene.

PubMed: 31371453
DOI: 10.1074/jbc.RA119.009601

Experimental method

SOLUTION NMR