GO:0034993 meiotic nuclear membrane microtubule tethering complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0034993 describes a nuclear membrane protein complex that connects the nuclear outer and inner membranes and links the nuclear lumen to cytoplasmic microtubules during meiosis.
• The complex is also known as the LINC complex (LInker of Nucleoskeleton and Cytoskeleton) or SUN-KASH complex, and in meiosis it is often called the telomere-associated LINC complex.
• In budding yeast, Mps2 links Csm4 and Mps3 to form a telomere-associated LINC complex that mediates meiotic chromosome movements.
• In mammals, KASH5 is a dynein-activating adaptor that couples the LINC complex to cytoplasmic dynein for meiotic chromosomal movements.
• SUN1 splice variants, including SUN1_888, SUN1_785, and SUN1_916, variably function in directional cell migration, highlighting isoform-specific roles of LINC components.
• The zygotene cilium controls meiotic chromosomal bouquet formation and germ cell morphogenesis, linking the LINC complex to ciliary and cytoskeletal dynamics.
Description
The meiotic nuclear membrane microtubule tethering complex (GO:0034993) is a nuclear membrane protein complex that connects the nuclear outer and inner membranes together and links the nuclear lumen to cytoplasmic microtubules during meiosis. This complex is essential for transmitting forces from the cytoplasm to the nucleus, enabling chromosome movements that are critical for proper meiotic recombination and chromosome segregation. In budding yeast, the complex is formed by Mps2, which links Csm4 and Mps3 to create a telomere-associated LINC complex. In mammals, KASH5 acts as a dynein-activating adaptor that couples the complex to cytoplasmic dynein, driving meiotic chromosomal movements. Researchers study GO:0034993 because defects in its components can lead to meiotic arrest, infertility, and developmental abnormalities. The complex is also implicated in directional cell migration through SUN1 splice variants, suggesting broader roles beyond meiosis. Understanding its assembly and regulation provides insights into nuclear positioning, cytoskeletal coupling, and germ cell development. This article synthesizes authoritative QuickGO data and verified PubMed literature to describe the components, assembly, molecular mechanism, and research methods for studying GO:0034993. It is intended for researchers seeking to model this complex using CRISPR-based approaches and to explore its roles in health and disease.
meiotic nuclear membrane microtubule tethering complex At A Glance
| GO ID | GO:0034993 |
|---|---|
| GO term | meiotic nuclear membrane microtubule tethering complex |
| Ontology | cellular_component |
| Synonym | LINC complex; LInker of Nucleoskeleton and Cytoskeleton complex; SUN-KASH complex |
| Major function | Connects nuclear outer and inner membranes and links nuclear lumen to cytoplasmic microtubules during meiosis |
| Cellular location | Nuclear membrane (inner and outer membranes) |
| Key components | SUN-domain proteins (e.g., Mps3, SUN1), KASH-domain proteins (e.g., Csm4, KASH5), and linker proteins (e.g., Mps2) |
| Associated processes | Meiotic chromosome movements, bouquet formation, homologous recombination, germ cell morphogenesis |
| Disease relevance | Infertility, meiotic arrest, developmental defects |
What Is GO:0034993?
GO:0034993, the meiotic nuclear membrane microtubule tethering complex, is a protein complex embedded in the nuclear membrane that physically connects the inner and outer nuclear membranes and bridges the nuclear lumen to cytoplasmic microtubules during meiosis. This connection allows forces generated by cytoplasmic motors to be transmitted to the nuclear envelope, facilitating chromosome movements such as the meiotic bouquet. The complex is synonymous with the LINC complex (LInker of Nucleoskeleton and Cytoskeleton) and the SUN-KASH complex, reflecting its core architecture of SUN-domain proteins in the inner membrane and KASH-domain proteins in the outer membrane.
Why Is meiotic nuclear membrane microtubule tethering complex Important in Cell Biology?
GO:0034993 is critical for meiosis because it transmits cytoplasmic forces to the nucleus, enabling chromosome movements that are required for homologous recombination and proper chromosome segregation. Disruption of this complex leads to meiotic defects, including failure of bouquet formation and impaired germ cell development, which can cause infertility. Additionally, components such as SUN1 splice variants influence directional cell migration, indicating roles beyond meiosis. Studying this complex therefore informs reproductive biology, developmental biology, and potential therapeutic targets for fertility disorders.
• Essential for meiotic chromosome movements and bouquet formation.
• Required for homologous recombination and proper chromosome segregation.
• Defects cause meiotic arrest and infertility in model organisms.
• Links nuclear envelope to cytoplasmic dynein via KASH5 adaptor function.
• SUN1 splice variants modulate directional cell migration.
• Involved in germ cell morphogenesis through zygotene cilium control.
• Provides a model for studying LINC complex assembly and function.
• Potential target for fertility-related diagnostics and therapeutics.
• Relevant to understanding nuclear positioning in development.
• Conserved from yeast to mammals, enabling cross-species research.
What Happens During meiotic nuclear membrane microtubule tethering complex?
Assembly of the telomere-associated LINC complex
In simple terms: Proteins come together at the nuclear envelope to form a bridge that connects chromosomes to the cytoskeleton.
In budding yeast, Mps2 links Csm4 and Mps3 to form a telomere-associated LINC complex. Mps3 is a SUN-domain protein in the inner nuclear membrane, while Csm4 is a KASH-domain protein in the outer membrane, and Mps2 acts as a linker between them. This assembly is essential for meiotic chromosome movements.
Coupling to cytoplasmic microtubules and dynein
In simple terms: The complex grabs onto molecular motors that pull chromosomes through the nucleus.
In mammals, KASH5 functions as a dynein-activating adaptor that couples the LINC complex to cytoplasmic dynein. This interaction allows dynein to generate forces that move chromosomes within the nucleus during meiosis.
Meiotic chromosome movements and bouquet formation
In simple terms: Chromosomes cluster together and move in a dance that helps them find their partners.
The complex mediates meiotic chromosomal movements, including the formation of the chromosomal bouquet, a conserved configuration where telomeres cluster at the nuclear envelope. The zygotene cilium controls this bouquet formation and germ cell morphogenesis.
Regulation by SUN1 splice variants
In simple terms: Different versions of the same protein can change how cells move.
SUN1 splice variants, including SUN1_888, SUN1_785, and predominant SUN1_916, variably function in directional cell migration. This suggests that alternative splicing regulates the complex's roles in different cellular contexts.
Key Genes Involved in GO:0034993 meiotic nuclear membrane microtubule tethering complex
The following genes and proteins are core components or regulators of the meiotic nuclear membrane microtubule tethering complex (GO:0034993).
| Gene | Major Role | Research Relevance |
|---|---|---|
| MPS3 | SUN-domain protein in inner nuclear membrane; core component of the LINC complex | Studied for its role in meiotic chromosome movements and nuclear envelope function |
| CSM4 | KASH-domain protein in outer nuclear membrane; interacts with Mps3 via Mps2 | Key for understanding telomere-associated LINC complex assembly |
| MPS2 | Linker protein connecting Csm4 and Mps3 | Essential for forming the telomere-associated LINC complex in budding yeast |
| KASH5 | Dynein-activating adaptor; couples LINC complex to cytoplasmic dynein | Critical for meiotic chromosomal movements and dynein regulation |
| SUN1 | Inner nuclear membrane SUN-domain protein; splice variants affect cell migration | Isoform-specific functions in directional cell migration |
| SUN2 | Inner nuclear membrane SUN-domain protein; forms LINC complexes with KASH proteins | Potential partner in meiotic and mitotic nuclear positioning |
| ZYGOTE CILIUM components | Control meiotic chromosomal bouquet and germ cell morphogenesis | Link ciliary function to meiotic chromosome dynamics |
| Dynein heavy chain | Cytoplasmic motor that generates force for chromosome movement | Target for understanding force transmission in meiosis |
| Dynactin | Dynein cofactor; may interact with KASH5 | Potential regulator of dynein-mediated meiotic movements |
| Telomere proteins | Anchor telomeres to the LINC complex during bouquet formation | Studied for meiosis-specific telomere modifications |
| Csm4 homologs | KASH-domain proteins in other organisms | Comparative studies of LINC complex evolution |
| Mps3 homologs | SUN-domain proteins in other organisms | Conserved mechanisms of nuclear envelope tethering |
| KASH-domain proteins | Outer membrane components that bind SUN proteins | General LINC complex architecture |
| SUN-domain proteins | Inner membrane components that interact with KASH proteins | Core of the SUN-KASH bridge |
| Microtubule-associated proteins | Facilitate microtubule attachment to the complex | Regulation of force transmission |
| Meiosis-specific telomere factors | Modify telomeres for bouquet formation | Link telomere biology to LINC complex function |
How Is meiotic nuclear membrane microtubule tethering complex Regulated?
The meiotic nuclear membrane microtubule tethering complex is regulated at multiple levels. In budding yeast, Mps2 acts as a linker that is essential for assembling the telomere-associated LINC complex, and its expression or availability may control complex formation. In mammals, KASH5 functions as a dynein-activating adaptor, and its activity is likely regulated by dynein cofactors such as dynactin. Additionally, alternative splicing of SUN1 produces variants (SUN1_888, SUN1_785, SUN1_916) that differentially affect directional cell migration, indicating post-transcriptional regulation. The zygotene cilium also influences bouquet formation, suggesting ciliary signaling may regulate the complex during meiosis.
meiotic nuclear membrane microtubule tethering complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| KASH5 | Meiotic arrest, infertility | Knockout mouse or cell model to study dynein activation |
| SUN1 | Developmental defects, cell migration disorders | Splice variant-specific knock-in models |
| MPS3 | Meiotic defects in yeast | Yeast knockout and point mutation studies |
| CSM4 | Impaired bouquet formation | Yeast knockout and live imaging |
| Zygotene cilium components | Germ cell morphogenesis defects | Zebrafish or mouse models with ciliary mutations |
Meiotic defects and infertility
Disruption of the meiotic nuclear membrane microtubule tethering complex leads to failures in chromosome movements, bouquet formation, and homologous recombination, resulting in meiotic arrest and infertility. KASH5 mutations or loss of function impair dynein-mediated chromosomal movements, which can cause germ cell aplasia. The zygotene cilium is also required for germ cell morphogenesis, and its dysfunction contributes to meiotic defects.
Developmental abnormalities
SUN1 splice variants influence directional cell migration, and their dysregulation may affect developmental processes beyond meiosis. Proper nuclear positioning is critical for tissue morphogenesis, and LINC complex components are implicated in developmental disorders.
Cancer and nuclear envelope defects
While direct links to cancer are not established for GO:0034993 specifically, LINC complex components in general are associated with nuclear envelope abnormalities in cancer. Further research is needed to determine whether meiotic-specific components play roles in oncogenesis.
From meiotic nuclear membrane microtubule tethering complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does KASH5 knockout impair meiotic chromosome movements? | Knockout mouse or cell line |
| How do SUN1 splice variants affect cell migration? | Point mutation or knock-in of specific isoforms |
| What is the role of Mps2 in LINC complex assembly? | Yeast knockout and tagged knock-in |
| Does overexpression of KASH5 enhance dynein recruitment? | Overexpression cell model |
| How does the zygotene cilium regulate bouquet formation? | Zebrafish knockout or knock-in |
| Can tagged Mps3 be used to track complex dynamics? | Tagged knock-in in yeast |
How to Study the meiotic nuclear membrane microtubule tethering complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Chromosome movements and bouquet formation | Meiotic progression in yeast and mouse |
| Co-immunoprecipitation | Protein-protein interactions | Identifying LINC complex components |
| Mass spectrometry | Proteomic composition | Detecting novel interactors |
| CRISPR knockout | Gene function | Assessing meiotic defects |
| Point mutation | Domain-specific functions | Dissecting dynein activation |
| RNA-seq | Transcript levels and splicing | SUN1 isoform expression |
| Fluorescence microscopy | Subcellular localization | Nuclear envelope tethering |
| Yeast genetics | Meiotic phenotypes | Bouquet formation assays |
Live-cell imaging of meiotic chromosome movements
Live-cell imaging using fluorescently tagged telomeres and nuclear envelope markers allows visualization of chromosome movements and bouquet formation in real time. This method is essential for assessing the function of the LINC complex in meiosis.
Proteomics and co-immunoprecipitation
Co-immunoprecipitation coupled with mass spectrometry can identify interacting partners of SUN and KASH domain proteins, revealing the composition of the meiotic nuclear membrane microtubule tethering complex.
Genetic knockout and point mutation studies
Knockout and point mutations in genes such as MPS3, CSM4, MPS2, and KASH5 are used to dissect the functional domains required for complex assembly and dynein activation.
Transcriptomics and splice variant analysis
RNA-seq and isoform-specific RT-PCR can reveal expression patterns of SUN1 splice variants and other components during meiosis and development.
How CRISPR Can Be Used to Study GO:0034993 meiotic nuclear membrane microtubule tethering complex
Knockout
CRISPR knockout of KASH5 or SUN1 can abolish the meiotic nuclear membrane microtubule tethering complex, leading to meiotic arrest and impaired chromosome movements. Knockout models are valuable for studying the complex's essential roles in meiosis and development.
Point Mutation
Point mutations in KASH5 or MPS3 can disrupt specific interactions, such as dynein binding or Mps2 linkage, without eliminating protein expression. These models help dissect domain-specific functions within the complex.
Knock-in
Knock-in of tagged versions of Mps3 or KASH5 allows real-time tracking of the complex via fluorescence microscopy. Knock-in of specific SUN1 splice variants can reveal isoform-specific functions in cell migration.
Overexpression
Overexpression of KASH5 or SUN1 can enhance dynein recruitment and alter nuclear positioning, providing insights into gain-of-function effects. Overexpression models are useful for studying complex assembly and cytoskeletal coupling.
How EDITGENE Supports meiotic nuclear membrane microtubule tethering complex Research
Researchers studying meiotic nuclear membrane microtubule tethering complex-related genes often need to determine whether a candidate gene is causally involved in meiotic chromosome movements, bouquet formation, or germ cell development. CRISPR-based models provide a precise way to test gene function and validate therapeutic targets.
Contact EDITGENE today to design your custom CRISPR model for meiotic nuclear membrane microtubule tethering complex research.
Frequently Asked Questions About meiotic nuclear membrane microtubule tethering complex
What is GO:0034993?
GO:0034993 is the meiotic nuclear membrane microtubule tethering complex, a protein complex that connects the nuclear inner and outer membranes and links the nuclear lumen to cytoplasmic microtubules during meiosis.
What genes are involved in meiotic nuclear membrane microtubule tethering complex?
Key genes include MPS3, CSM4, MPS2, KASH5, and SUN1, which encode SUN-domain, KASH-domain, and linker proteins.
What is the function of the LINC complex in meiosis?
The LINC complex transmits cytoplasmic forces to the nucleus, enabling chromosome movements and bouquet formation required for homologous recombination.
How is the meiotic nuclear membrane microtubule tethering complex regulated?
It is regulated by protein interactions, alternative splicing of SUN1, and dynein cofactors such as dynactin.
What diseases are associated with defects in this complex?
Defects can cause meiotic arrest, infertility, and developmental abnormalities due to impaired chromosome movements.
What model systems are used to study GO:0034993?
Budding yeast, mouse, and zebrafish models are commonly used to study meiotic chromosome movements and LINC complex assembly.
How can CRISPR be used to study this complex?
CRISPR knockout, point mutation, knock-in, and overexpression models allow precise dissection of gene function in meiosis.
What is the role of KASH5 in meiosis?
KASH5 is a dynein-activating adaptor that couples the LINC complex to cytoplasmic dynein for meiotic chromosomal movements.
What is the meiotic bouquet and why is it important?
The meiotic bouquet is a conserved chromosome configuration where telomeres cluster at the nuclear envelope, promoting homologous pairing.
How does SUN1 alternative splicing affect cell migration?
SUN1 splice variants such as SUN1_888, SUN1_785, and SUN1_916 differentially influence directional cell migration.
Conclusion
The meiotic nuclear membrane microtubule tethering complex (GO:0034993) is a conserved LINC/SUN-KASH complex essential for meiotic chromosome movements, bouquet formation, and germ cell development. Its components, including Mps2, Mps3, Csm4, KASH5, and SUN1, are critical for linking the nuclear envelope to the cytoskeleton. Defects in this complex lead to meiotic arrest and infertility, making it a key research focus. CRISPR-based models, including knockout, point mutation, knock-in, and overexpression, provide powerful tools to dissect the molecular mechanisms of GO:0034993. EDITGENE offers comprehensive services to accelerate this research and uncover therapeutic targets for fertility and developmental disorders.
References
- 1. Shibuya H et al.. 2014. The meiosis-specific modification of mammalian telomeres.. Cell Cycle 13(13):2024-8 PMID: 24870409
- 2. Fan J et al.. 2020. Mps2 links Csm4 and Mps3 to form a telomere-associated LINC complex in budding yeast.. Life Sci Alliance 3(12) PMID: 32967926
- 3. Agrawal R et al.. 2022. The KASH5 protein involved in meiotic chromosomal movements is a novel dynein activating adaptor.. Elife 11 PMID: 35703493
- 4. Nishioka Y et al.. 2016. SUN1 splice variants, SUN1_888, SUN1_785, and predominant SUN1_916, variably function in directional cell migration.. Nucleus 7(6):572-584 PMID: 27858498
- 5. Mytlis A et al.. 2022. Control of meiotic chromosomal bouquet and germ cell morphogenesis by the zygotene cilium.. Science 376(6599):eabh3104 PMID: 35549308
