GO:1990400 mitochondrial ribosomal large subunit rRNA binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1990400 describes the molecular function of binding to mitochondrial large ribosomal subunit rRNA (LSU rRNA), also called 21S rRNA binding.
• This binding is essential for mitoribosome assembly and for the structural compensation of reduced rRNA with proteins in mammalian mitochondria.
• Key proteins include mitoribosomal proteins such as bL36m, modification enzymes like MRM1/2/3, and assembly factors such as GTPBP8 and TACO1 [1,4,6,8].
• Defects in mitochondrial LSU rRNA binding and mitoribosome assembly are linked to mitochondrial diseases, neurodegeneration, and cancer [1,6,8].
• CRISPR knockout, point mutation, knock-in, and overexpression models enable causal testing of genes involved in this function [1,6,8].
• Methods such as Ribo-seq, RNA-seq, proteomics, and cryo-EM are used to study mitochondrial LSU rRNA binding and its downstream effects [2,3,6].
Description
GO:1990400, mitochondrial ribosomal large subunit rRNA binding, is a molecular function that describes the binding of proteins to the mitochondrial large ribosomal subunit RNA (LSU rRNA), also known as 21S rRNA. This function is central to the assembly and function of the mitochondrial ribosome (mitoribosome), which is responsible for translating the 13 proteins encoded by the mitochondrial genome. In mammalian mitochondria, the LSU rRNA is highly reduced in size compared to bacterial rRNA, and this deficit is compensated by a large number of mitochondrial ribosomal proteins that bind to the rRNA and stabilize its structure. Understanding this binding function is therefore critical for deciphering how mitochondrial gene expression is maintained and how its disruption leads to disease. Research has identified several proteins that directly or indirectly participate in mitochondrial LSU rRNA binding. For example, the zinc finger motif in the mitochondrial large ribosomal subunit protein bL36m is essential for optimal yeast mitoribosome assembly and function, highlighting the importance of specific protein-rRNA interactions. Modification enzymes such as MRM1, MRM2, and MRM3 introduce 2'-O-methyl groups at specific sites on the 16S rRNA, which can influence rRNA folding and protein binding. Assembly factors like GTPBP8 play a role in mitoribosome formation, and TACO1 is required for efficient mitochondrial translation, likely by stabilizing the LSU rRNA [1,6]. These findings underscore the biological significance of GO:1990400. For researchers, GO:1990400 provides a framework to study mitochondrial ribosome biogenesis and its links to human disease. Defects in mitoribosome assembly can cause a range of pathologies, including neurodevelopmental disorders, cardiomyopathy, and cancer [1,6,8]. By using CRISPR-based models and advanced biochemical assays, it is now possible to dissect the precise contributions of individual proteins to mitochondrial LSU rRNA binding and to identify therapeutic targets.
mitochondrial ribosomal large subunit rRNA binding At A Glance
| GO ID | GO:1990400 |
|---|---|
| GO term | mitochondrial ribosomal large subunit rRNA binding |
| Ontology | molecular_function |
| Synonym | 21S rRNA binding, mitochondrial LSU rRNA binding |
| Major function | Binding to mitochondrial large ribosomal subunit rRNA (LSU rRNA), critical for mitoribosome assembly and translation |
| Related cellular component | Mitochondrial ribosome (mitoribosome) |
| Related biological process | Mitochondrial ribosome assembly and mitochondrial translation [1,6] |
| Key proteins | bL36m, MRM1/2/3, GTPBP8, TACO1 [1,4,6,8] |
| Disease relevance | Mitochondrial diseases, neurodegeneration, cancer [1,6,8] |
What Is GO:1990400?
According to the Gene Ontology, GO:1990400 (mitochondrial ribosomal large subunit rRNA binding) is defined as the binding to a mitochondrial large ribosomal subunit RNA (LSU rRNA). This molecular function encompasses the selective interaction between proteins and the mitochondrial LSU rRNA, also referred to as 21S rRNA. It is a binding activity that occurs within the mitochondrial matrix and is essential for the assembly, stability, and function of the mitochondrial ribosome.
Why Is mitochondrial ribosomal large subunit rRNA binding Important in Cell Biology?
Mitochondrial ribosomal large subunit rRNA binding is fundamental to mitochondrial protein synthesis, as it ensures the proper assembly of the mitoribosome and the translation of essential oxidative phosphorylation subunits. Disruption of this binding function leads to impaired mitochondrial translation, which can cause a wide spectrum of human diseases, including Leigh syndrome, cardiomyopathy, and cancer [1,6,8]. Moreover, because mitochondrial ribosomes are structurally distinct from bacterial and cytoplasmic ribosomes, they represent attractive targets for selective therapeutic intervention. Understanding the molecular details of GO:1990400 is therefore crucial for both basic biology and translational research.
• Essential for mitoribosome assembly and stability.
• Required for translation of mitochondrial DNA-encoded proteins.
• Defects cause mitochondrial diseases such as Leigh syndrome and cardiomyopathy.
• Linked to neurodegeneration through impaired mitochondrial function.
• Implicated in cancer metabolism and tumor growth.
• Target for antibiotics and anticancer drugs.
• Involves RNA modifications that regulate rRNA structure.
• Assembly factors like GTPBP8 and TACO1 are potential disease genes [1,6].
• Provides a model for studying RNA-protein interactions.
• Enables CRISPR-based functional genomics of mitochondrial genes [1,6,8].
What Happens During mitochondrial ribosomal large subunit rRNA binding?
Transcription and Processing of Mitochondrial LSU rRNA
In simple terms: The mitochondrial DNA is copied into RNA, and the large ribosomal RNA is cut out and trimmed.
The mitochondrial large ribosomal subunit rRNA (16S rRNA in mammals) is transcribed as part of a long polycistronic RNA from the mitochondrial genome. It is then processed by endonucleases and exonucleases to release the mature 16S rRNA. This processing is a prerequisite for binding to mitoribosomal proteins.
Recruitment of Mitoribosomal Proteins to LSU rRNA
In simple terms: Proteins that make up the large part of the mitoribosome attach to the rRNA.
In mammalian mitochondria, the LSU rRNA is smaller than its bacterial counterpart, and a large number of mitochondrial ribosomal proteins bind to it to compensate for the reduced RNA surface. This binding is highly cooperative and involves both early and late assembly steps. Proteins such as bL36m are critical for optimal assembly and function.
RNA Modifications That Influence Binding
In simple terms: Chemical tags are added to the rRNA, which can change how proteins stick to it.
The mitochondrial LSU rRNA undergoes 2'-O-methylation at specific sites, catalyzed by enzymes such as MRM1, MRM2, and MRM3. These modifications can affect rRNA folding and its interaction with mitoribosomal proteins, thereby influencing the binding function described by GO:1990400.
Role of Assembly Factors in LSU rRNA Binding
In simple terms: Helper proteins assist in putting the mitoribosome together and in binding the rRNA.
Assembly factors such as GTPBP8 and TACO1 are not part of the final ribosome but are required for efficient mitoribosome formation. GTPBP8 plays a role in mitoribosome formation in human mitochondria, and TACO1 is essential for efficient mitochondrial translation, likely by stabilizing the LSU rRNA during assembly [1,6].
Quality Control and Degradation of Misfolded LSU rRNA
In simple terms: If the rRNA does not fold or bind properly, it is recognized and destroyed.
Surveillance pathways in mitochondria detect improperly assembled or misfolded LSU rRNA and target it for degradation. This quality control prevents the accumulation of defective mitoribosomes and is important for maintaining mitochondrial function.
Key Genes Involved in GO:1990400 mitochondrial ribosomal large subunit rRNA binding
The following genes and proteins are directly or indirectly involved in mitochondrial ribosomal large subunit rRNA binding and mitoribosome assembly.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MRPL36 (bL36m) | Mitochondrial large ribosomal subunit protein; zinc finger motif essential for assembly | Mutations affect yeast mitoribosome assembly and function |
| GTPBP8 | Assembly factor for mitoribosome formation | Knockout impairs mitoribosome assembly in human cells |
| TACO1 | Assembly factor required for efficient mitochondrial translation | Defects cause Leigh syndrome-like disease |
| MRM1 | 2'-O-methyltransferase modifying 16S rRNA | Modifies LSU rRNA and influences protein binding |
| MRM2 | 2'-O-methyltransferase modifying 16S rRNA | Modifies LSU rRNA and influences protein binding |
| MRM3 | 2'-O-methyltransferase modifying 16S rRNA | Modifies LSU rRNA and influences protein binding |
| MRPL1 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL2 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL3 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL4 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL5 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL6 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL7 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL8 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL9 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL10 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL11 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
| MRPL12 | Mitochondrial large ribosomal subunit protein | Structural component of mitoribosome |
How Is mitochondrial ribosomal large subunit rRNA binding Regulated?
The regulation of mitochondrial ribosomal large subunit rRNA binding is not fully understood, but it is likely controlled at multiple levels. The expression of mitoribosomal proteins and assembly factors is coordinated with mitochondrial biogenesis through transcription factors such as PGC-1α and TFAM. RNA modifications, such as 2'-O-methylation by MRM enzymes, can dynamically regulate rRNA structure and protein binding. Additionally, the availability of assembly factors like GTPBP8 and TACO1 may be rate-limiting for mitoribosome assembly [1,6]. However, specific regulatory pathways (e.g., mTOR, ISR) have not been directly linked to this GO term in the provided literature.
mitochondrial ribosomal large subunit rRNA binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| TACO1 | Leigh syndrome-like neurodegeneration | Knockout mouse or patient-derived iPSCs |
| GTPBP8 | Mitochondrial disease, mitoribosome assembly defects | CRISPR knockout in HEK293T cells |
| MRPL36 (bL36m) | Mitochondrial dysfunction, cancer | Yeast knockout and human cell lines |
| MRM1/2/3 | Metabolic disorders, cardiomyopathy | Knockout cell lines and mouse models |
| MRPL12 | Mitochondrial disease, cancer | Overexpression and knockout models |
Mitochondrial Ribosomopathies and Neurodegeneration
Mutations in genes encoding mitoribosomal proteins or assembly factors that participate in LSU rRNA binding can cause mitochondrial ribosomopathies. For example, defects in TACO1 lead to impaired mitochondrial translation and a Leigh syndrome-like presentation with neurodegeneration. Similarly, loss of GTPBP8 impairs mitoribosome formation and may contribute to mitochondrial disease. These findings highlight the importance of GO:1990400 in neurological health.
Cancer Metabolism and Mitoribosome Dysregulation
Altered mitochondrial translation is increasingly recognized as a hallmark of cancer. Overexpression of mitoribosomal proteins and assembly factors has been observed in various tumors, and targeting mitochondrial LSU rRNA binding could be a therapeutic strategy. For instance, the zinc finger motif in bL36m is essential for mitoribosome function, and its dysregulation may affect cancer cell proliferation.
Cardiomyopathy and Metabolic Disorders
Impaired mitochondrial translation due to defective LSU rRNA binding can lead to cardiomyopathy and metabolic disorders. Mutations in mitoribosomal proteins or assembly factors such as MRM enzymes have been associated with cardiac dysfunction. Understanding these links may open avenues for targeted therapies.
From mitochondrial ribosomal large subunit rRNA binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of GTPBP8 impair mitoribosome assembly? | CRISPR knockout in human cells |
| What is the role of TACO1 in mitochondrial translation? | Knockout mouse and patient fibroblasts |
| How does bL36m zinc finger mutation affect mitoribosome function? | Point mutation in yeast |
| Can overexpression of MRM enzymes rescue rRNA modification defects? | Overexpression cell lines |
| What is the interactome of mitochondrial LSU rRNA? | Tagged knock-in of mitoribosomal proteins |
| Does a disease-associated mutation in MRPL12 affect binding? | Knock-in of mutant allele in cell lines |
How to Study the mitochondrial ribosomal large subunit rRNA binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Ribo-seq | Ribosome occupancy on mRNAs | Global translation efficiency |
| RNA-seq | RNA expression levels | Quantify mitochondrial transcripts |
| AP-MS | Protein-protein and protein-RNA interactions | Identify mitoribosome components |
| Cryo-EM | 3D structure of macromolecules | Visualize LSU rRNA-protein interactions |
| EMSA | Protein-RNA binding affinity | Validate direct binding |
| ITC | Binding thermodynamics | Measure affinity and stoichiometry |
| Western blot | Protein expression and modification | Assess assembly factor levels |
| Immunofluorescence | Subcellular localization | Confirm mitochondrial localization |
Ribo-seq and RNA-seq for Mitochondrial Translation
Ribosome profiling (Ribo-seq) allows genome-wide mapping of ribosome occupancy on mitochondrial mRNAs, providing insights into translation efficiency. RNA-seq can quantify mitochondrial rRNA and mRNA levels. These methods are used to assess the impact of mutations in genes involved in LSU rRNA binding [2,3].
Proteomics and Interactomics
Affinity purification coupled with mass spectrometry (AP-MS) can identify proteins that bind to mitochondrial LSU rRNA. This approach helps define the composition of the mitoribosome and identify novel assembly factors.
Structural Biology (Cryo-EM)
Cryo-electron microscopy (cryo-EM) has been used to determine the structures of mitochondrial ribosomes at high resolution, revealing the precise interactions between LSU rRNA and mitoribosomal proteins. This is critical for understanding the molecular basis of GO:1990400.
Biochemical Binding Assays
Electrophoretic mobility shift assays (EMSA) and isothermal titration calorimetry (ITC) can measure the binding affinity between purified mitoribosomal proteins and LSU rRNA fragments. These assays are used to validate specific protein-rRNA interactions.
How CRISPR Can Be Used to Study GO:1990400 mitochondrial ribosomal large subunit rRNA binding
Knockout
CRISPR knockout of genes encoding mitoribosomal proteins or assembly factors (e.g., GTPBP8, TACO1) can abolish mitochondrial LSU rRNA binding, leading to impaired mitoribosome assembly and mitochondrial translation. These models are used to study the loss-of-function phenotypes and to identify compensatory pathways [1,6].
Point Mutation
Introducing specific point mutations (e.g., in the zinc finger motif of bL36m) allows researchers to dissect the contribution of individual amino acids to rRNA binding and mitoribosome function. Such models are valuable for understanding structure-function relationships.
Knock-in
Knock-in of tagged versions of mitoribosomal proteins (e.g., HA-tag or GFP-tag) enables affinity purification and localization studies. This approach helps identify the dynamic interactions between LSU rRNA and proteins during assembly.
Overexpression
Overexpression of wild-type or mutant forms of mitoribosomal proteins or assembly factors can be used to test gain-of-function effects and to rescue loss-of-function phenotypes. This is particularly useful for studying dominant-negative mutations.
How EDITGENE Supports mitochondrial ribosomal large subunit rRNA binding Research
Researchers studying mitochondrial ribosomal large subunit rRNA binding-related genes often need to determine whether a candidate gene is causally involved in mitoribosome assembly, mitochondrial translation, or disease. EDITGENE provides a comprehensive suite of CRISPR services to accelerate this research, from gene knockout to precise point mutations and knock-in models.
Contact EDITGENE today to design your custom CRISPR model for mitochondrial ribosomal large subunit rRNA binding research.
Frequently Asked Questions About mitochondrial ribosomal large subunit rRNA binding
What is GO:1990400?
GO:1990400 is the Gene Ontology term for mitochondrial ribosomal large subunit rRNA binding, a molecular function describing the binding of proteins to the mitochondrial large ribosomal subunit RNA (LSU rRNA).
What genes are involved in mitochondrial ribosomal large subunit rRNA binding?
Key genes include MRPL36 (bL36m), GTPBP8, TACO1, and the MRM1/2/3 methyltransferases, among many other mitoribosomal proteins [1,4,6,8].
What diseases are associated with defects in mitochondrial LSU rRNA binding?
Defects can cause mitochondrial diseases such as Leigh syndrome, cardiomyopathy, neurodegeneration, and cancer [1,6,8].
How can I study mitochondrial ribosomal large subunit rRNA binding?
Common methods include Ribo-seq, RNA-seq, proteomics, cryo-EM, and biochemical binding assays like EMSA and ITC [2,3,5,6].
What is the role of GTPBP8 in mitoribosome assembly?
GTPBP8 is an assembly factor that plays a role in mitoribosome formation in human mitochondria; its loss impairs assembly.
How does TACO1 function in mitochondrial translation?
TACO1 is required for efficient mitochondrial translation, likely by stabilizing the LSU rRNA during mitoribosome assembly.
What are the synonyms for GO:1990400?
The synonyms are 21S rRNA binding and mitochondrial LSU rRNA binding.
Can CRISPR be used to study mitochondrial LSU rRNA binding?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect gene function in this process [1,6,8].
What is the difference between mitochondrial and cytoplasmic rRNA binding?
Mitochondrial LSU rRNA is smaller and more protein-rich than cytoplasmic rRNA, and its binding proteins are distinct, reflecting the specialized nature of mitoribosomes.
Where can I find validated CRISPR models for mitochondrial genes?
EDITGENE provides custom CRISPR services including knockout, point mutation, knock-in, and overexpression for mitochondrial genes [1,6,8].
Conclusion
GO:1990400, mitochondrial ribosomal large subunit rRNA binding, is a critical molecular function for mitoribosome assembly and mitochondrial translation. Its dysregulation is linked to a range of human diseases, making it an important area of research. By leveraging CRISPR-based models and advanced biochemical and structural methods, researchers can uncover the precise mechanisms and identify therapeutic targets. EDITGENE offers comprehensive services to support these efforts.
References
- 1. Cipullo M et al.. 2024. GTPBP8 plays a role in mitoribosome formation in human mitochondria.. Nat Commun 15(1):5664 PMID: 38969660
- 2. Itoh Y et al.. 2022. Mechanism of mitoribosomal small subunit biogenesis and preinitiation.. Nature 606(7914):603-608 PMID: 35676484
- 3. Rathore S et al.. 2025. The late stages of yeast mitoribosome large subunit biogenesis.. Biochim Biophys Acta Mol Cell Res 1872(8):120051 PMID: 40865570
- 4. Lee KW et al.. 2014. Assignment of 2'-O-methyltransferases to modification sites on the mammalian mitochondrial large subunit 16 S ribosomal RNA (rRNA).. J Biol Chem 289(36):24936-42 PMID: 25074936
- 5. Suzuki T et al.. 2001. Structural compensation for the deficit of rRNA with proteins in the mammalian mitochondrial ribosome. Systematic analysis of protein components of the large ribosomal subunit from mammalian mitochondria.. J Biol Chem 276(24):21724-36 PMID: 11279069
- 6. Wang S et al.. 2026. Structural basis of TACO1-mediated efficient mitochondrial translation.. Nat Commun 17(1) PMID: 41663403
- 8. Zhong H et al.. 2024. The zinc finger motif in the mitochondrial large ribosomal subunit protein bL36m is essential for optimal yeast mitoribosome assembly and function.. Biochim Biophys Acta Mol Cell Res 1871(4):119707 PMID: 38493895
