Target type: biologicalprocess
The directed movement of mRNA from the nucleus to the cytoplasm. [GOC:ma]
mRNA export from the nucleus is a tightly regulated process that ensures the delivery of mature messenger RNA (mRNA) molecules from the site of transcription in the nucleus to the cytoplasm, where they can be translated into proteins. This process involves a series of intricate steps, including:
1. **Transcription and mRNA processing:** Within the nucleus, DNA is transcribed into precursor mRNA (pre-mRNA), which undergoes several modifications, including capping, splicing, and polyadenylation. These modifications are essential for the stability and translation efficiency of the mRNA.
2. **Recognition by nuclear export receptors:** Once the pre-mRNA is processed, it is recognized by nuclear export receptors (NXRs), specifically the heterodimer composed of NXF1 and NXT1. These receptors bind to a specific sequence within the mRNA, often found near the 5' cap, known as the nuclear export signal (NES).
3. **Passage through nuclear pores:** The mRNA-NXR complex then interacts with the nuclear pore complex (NPC), which acts as a gatekeeper between the nucleus and cytoplasm. The NPC is a large protein complex that forms channels through the nuclear envelope, allowing selective transport of molecules.
4. **GTP-dependent transport:** The movement of the mRNA-NXR complex through the NPC is driven by a GTP-dependent mechanism involving the Ran protein, a small GTPase. RanGTP, present in the cytoplasm, binds to the NXR, promoting the release of the mRNA into the cytoplasm.
5. **Cytoplasmic fate:** Once in the cytoplasm, the mRNA can associate with ribosomes and begin translation. The NXR is recycled back to the nucleus, ready for another round of mRNA export.
The efficiency of mRNA export is crucial for gene expression and cellular function. Dysregulation of this process can lead to various diseases, including cancer and neurodegenerative disorders.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Serine/threonine-protein kinase SMG1 | A serine/threonine-protein kinase SMG1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q96Q15] | Homo sapiens (human) |
| Eukaryotic initiation factor 4A-III | A eukaryotic initiation factor 4A-III that is encoded in the genome of human. [PRO:DNx, UniProtKB:P38919] | Homo sapiens (human) |
| Eukaryotic translation initiation factor 4E | A eukaryotic translation initiation factor 4E that is encoded in the genome of human. [PRO:DNx, UniProtKB:P06730] | Homo sapiens (human) |
| Exportin-1 | An exportin-1 that is encoded in the genome of human. [PRO:CNA] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| coumarin | 2H-chromen-2-one: coumarin derivative | coumarins | fluorescent dye; human metabolite; plant metabolite |
| osthol | osthol: from Cnidium monnieri and Angelica pubescens (both Apiaceae); structure given in first source | botanical anti-fungal agent; coumarins | metabolite |
| herniarin | herniarin : A member of the class of coumarins that is coumarin substituted by a methoxy group at position 7. herniarin: methoxy analog of umbelliferone; structure | coumarins | fluorochrome |
| cgp 60474 | substituted aniline | ||
| sirolimus | sirolimus : A macrolide lactam isolated from Streptomyces hygroscopicus consisting of a 29-membered ring containing 4 trans double bonds, three of which are conjugated. It is an antibiotic, immunosupressive and antineoplastic agent. Sirolimus: A macrolide compound obtained from Streptomyces hygroscopicus that acts by selectively blocking the transcriptional activation of cytokines thereby inhibiting cytokine production. It is bioactive only when bound to IMMUNOPHILINS. Sirolimus is a potent immunosuppressant and possesses both antifungal and antineoplastic properties. | antibiotic antifungal drug; cyclic acetal; cyclic ketone; ether; macrolide lactam; organic heterotricyclic compound; secondary alcohol | antibacterial drug; anticoronaviral agent; antineoplastic agent; bacterial metabolite; geroprotector; immunosuppressive agent; mTOR inhibitor |
| 6-mercapto-7-methylguanosine | 6-mercapto-7-methylguanosine: structure given in first source | ||
| ci 940 | leptomycin : A complex, very long chain, polyunsaturated fatty acid whose core structure comprises 8-oxononadeca-2,10,12,16,18-pentaenoic acid having methyl substituents at positions 3, 5, 7, 9, 11 and 15 and a 3,6-dihydropyran-6-one-2-yl group at position 19. | hydroxy polyunsaturated fatty acid; leptomycin | antifungal agent; bacterial metabolite |
| hippuristanol | hippuristanol: from the gorgonian Isis hippuris | ||
| cgp 57380 | CGP 57380: inhibits the mitogen-activated protein kinase-interacting kinase Mnk1 | pyrazolopyrimidine | |
| kpt-185 | KPT-185: binds CRM1 to inhibit nuclear export; has antineoplastic activity | ||
| selinexor | selinexor: inhibits karyopherin XPO1 | ||
| 7-methyl-GTP | guanosine 5'-phosphate |