1
|
Liu S, Chen H, Yin Y, Lu D, Gao G, Li J, Bai XC, Zhang X. Inhibition of FAM46/TENT5 activity by BCCIPα adopting a unique fold. SCIENCE ADVANCES 2023; 9:eadf5583. [PMID: 37018411 PMCID: PMC10075960 DOI: 10.1126/sciadv.adf5583] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/07/2023] [Indexed: 06/19/2023]
Abstract
The FAM46 (also known as TENT5) proteins are noncanonical poly(A) polymerases (PAPs) implicated in regulating RNA stability. The regulatory mechanisms of FAM46 are poorly understood. Here, we report that the nuclear protein BCCIPα, but not the alternatively spliced isoform BCCIPβ, binds FAM46 and inhibits their PAP activity. Unexpectedly, our structures of the FAM46A/BCCIPα and FAM46C/BCCIPα complexes show that, despite sharing most of the sequence and differing only at the C-terminal portion, BCCIPα adopts a unique structure completely different from BCCIPβ. The distinct C-terminal segment of BCCIPα supports the adoption of the unique fold but does not directly interact with FAM46. The β sheets in BCCIPα and FAM46 pack side by side to form an extended β sheet. A helix-loop-helix segment in BCCIPα inserts into the active site cleft of FAM46, thereby inhibiting the PAP activity. Our results together show that the unique fold of BCCIPα underlies its interaction with and functional regulation of FAM46.
Collapse
Affiliation(s)
- Shun Liu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Hua Chen
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yan Yin
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Defen Lu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Guoming Gao
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jie Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xuewu Zhang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
2
|
Choi WS, Liu B, Shen Z, Yang W. Structure of human BCCIP and implications for binding and modification of partner proteins. Protein Sci 2021; 30:693-699. [PMID: 33452718 DOI: 10.1002/pro.4026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 11/09/2022]
Abstract
BCCIP was isolated based on its interactions with tumor suppressors BRCA2 and p21. Knockdown or knockout of BCCIP causes embryonic lethality in mice. BCCIP deficient cells exhibit impaired cell proliferation and chromosome instability. BCCIP also plays a key role in biogenesis of ribosome 60S subunits. BCCIP is conserved from yeast to humans, but it has no discernible sequence similarity to proteins of known structures. Here we report two crystal structures of an N-terminal truncated human BCCIPβ, consisting of residues 61-314. Structurally BCCIP is similar to GCN5-related acetyltransferases (GNATs) but contains different sequence motifs. Moreover, both acetyl-CoA and substrate-binding grooves are altered in BCCIP. A large 19-residue flap over the putative CoA binding site adopts either an open or closed conformation in BCCIP. The substrate binding groove is significantly reduced in size and is positively charged despite the acidic isoelectric point of BCCIP. BCCIP has potential binding sites for partner proteins and may have enzymatic activity.
Collapse
Affiliation(s)
- Woo Suk Choi
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| | - Bochao Liu
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey, USA
| | - Zhiyuan Shen
- Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey, USA
| | - Wei Yang
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
3
|
Ye C, Liu B, Lu H, Liu J, Rabson AB, Jacinto E, Pestov DG, Shen Z. BCCIP is required for nucleolar recruitment of eIF6 and 12S pre-rRNA production during 60S ribosome biogenesis. Nucleic Acids Res 2021; 48:12817-12832. [PMID: 33245766 PMCID: PMC7736804 DOI: 10.1093/nar/gkaa1114] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/28/2020] [Accepted: 11/05/2020] [Indexed: 01/25/2023] Open
Abstract
Ribosome biogenesis is a fundamental process required for cell proliferation. Although evolutionally conserved, the mammalian ribosome assembly system is more complex than in yeasts. BCCIP was originally identified as a BRCA2 and p21 interacting protein. A partial loss of BCCIP function was sufficient to trigger genomic instability and tumorigenesis. However, a complete deletion of BCCIP arrested cell growth and was lethal in mice. Here, we report that a fraction of mammalian BCCIP localizes in the nucleolus and regulates 60S ribosome biogenesis. Both abrogation of BCCIP nucleolar localization and impaired BCCIP-eIF6 interaction can compromise eIF6 recruitment to the nucleolus and 60S ribosome biogenesis. BCCIP is vital for a pre-rRNA processing step that produces 12S pre-rRNA, a precursor to the 5.8S rRNA. However, a heterozygous Bccip loss was insufficient to impair 60S biogenesis in mouse embryo fibroblasts, but a profound reduction of BCCIP was required to abrogate its function in 60S biogenesis. These results suggest that BCCIP is a critical factor for mammalian pre-rRNA processing and 60S generation and offer an explanation as to why a subtle dysfunction of BCCIP can be tumorigenic but a complete depletion of BCCIP is lethal.
Collapse
Affiliation(s)
- Caiyong Ye
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Bochao Liu
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Huimei Lu
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Jingmei Liu
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Arnold B Rabson
- Department of Pharmacology, and The Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Dimitri G Pestov
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Zhiyuan Shen
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| |
Collapse
|