Mir-6 microRNA precursor

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mir-6 microRNA precursor
RF00143.jpg
Identifiers
Symbolmir-6
Rfam RF00143
miRBase MI0000124
miRBase family MIPF0000119
Other data
RNA type Gene; miRNA
Domain(s) Eukaryota
GO 0035195 0035068
SO 0001244
PDB structures PDBe

The mir-6 microRNA precursor is a precursor microRNA specific to Drosophila species. In Drosophila melanogaster there are three mir-6 paralogs called dme-mir-6-1, dme-mir-6-2, dme-mir-6-3, which are clustered together in the genome. The extents of these hairpin precursors are estimated based on hairpin prediction. Each precursor is generated following the cleavage of a longer primary transcript in the nucleus, and is exported in the cytoplasm. In the cytoplasm, precursors are further processed by the enzyme Dicer, generating ~22 nucleotide products from each arm of the hairpin. The products generated from the 3' arm of each mir-6 precursor have identical sequences. Both 5' and 3' mature products are experimentally validated. Experimental data suggests that the mature products of mir-6 hairpins are expressed in the early embryo of Drosophila and target apoptotic genes such as hid, grim and rpr. [1]

Contents

Near perfect complementarity has been observed between miR-5 and miR-6 at 20/21 nucleotides. [2] However, miR-5 is only related on a minor level to any of the three respective miR-6 sequences. miR-6 genes reside in a gene cluster containing other non-K-box family miRNAs, including miRNAs-3 and-309, and the Brd box family gene mir-4. Alignment has shown miR-6 to share the same family motif as miR-11 and miR-2b, together making up the mir-2 clan. There is, however, little similarity in the 3' ends between these clan members.

Apoptotic regulation

mir-6 plays a key role in the regulation of early apoptosis. Indeed, there is a much increased apoptotic rate in miR-6-depleted embryos compared with control embryos, indicating that mir-6 acts to suppress apoptosis. The pro-apoptotic factor Hid is controlled solely by miR-6, which sees its regulation at a post-transcriptional level. miR-6-depleted embryos have been found to show the strongest phenotype of all miR-2 family members, explained by their interaction with hid, the pro-apoptotic gene with the broadest expression and strongest proapoptotic effect. [3] Embryos injected with mir-6 antisense failed to differentiate normal internal and external structures, with the number of apoptotic cells much increased compared to wildtype cells. [1] Further work into this with miR-6-depleted blastoderm embryos found pole cell formation at the posterior end of the anteroposterior axis to be disrupted, despite normality of both cellularisation and early pattern formation. [1]

Related Research Articles

microRNA Small non-coding ribonucleic acid molecule

A microRNA is a small non-coding RNA molecule found in plants, animals and some viruses, that functions in RNA silencing and post-transcriptional regulation of gene expression. miRNAs function via base-pairing with complementary sequences within mRNA molecules. As a result, these mRNA molecules are silenced, by one or more of the following processes: (1) Cleavage of the mRNA strand into two pieces, (2) Destabilization of the mRNA through shortening of its poly(A) tail, and (3) Less efficient translation of the mRNA into proteins by ribosomes.

lin-4 microRNA precursor

In molecular biology lin-4 is a microRNA (miRNA) that was identified from a study of developmental timing in the nematode Caenorhabditis elegans. It was the first to be discovered of the miRNAs, a class of non-coding RNAs involved in gene regulation. miRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a 21 nucleotide product. The extents of the hairpin precursors are not generally known and are estimated based on hairpin prediction. The products are thought to have regulatory roles through complete or partial complementarity to mRNA. The lin-4 gene has been found to lie within a 4.11kb intron of a separate host gene.

mir-103/107 microRNA precursor

The miR-103 microRNA precursor, is a short non-coding RNA gene involved in gene regulation. miR-103 and miR-107 have now been predicted or experimentally confirmed in human.

mir-192/215 microRNA precursor

The miR-192 microRNA precursor, is a short non-coding RNA gene involved in gene regulation. miR-192 and miR-215 have now been predicted or experimentally confirmed in mouse and human.

mir-46/mir-47/mir-281 microRNA precursor family

In molecular biology, mir-46 and mir-47 are microRNA expressed in C. elegans from related hairpin precursor sequences. The predicted hairpin precursor sequences for Drosophila mir-281 are also related and, hence, belong to this family. The hairpin precursors are predicted based on base pairing and cross-species conservation; their extents are not known. In this case, the mature sequences are expressed from the 3' arms of the hairpin precursors.

mir-8/mir-141/mir-200 microRNA precursor family

The miR-8 microRNA precursor, is a short non-coding RNA gene involved in gene regulation. miR-8 in Drosophila melanogaster is expressed from the 3' arm of related precursor hairpins, along with miR-200, miR-236, miR-429 and human and mouse homolog miR-141. Members of this precursor family have now been predicted or experimentally confirmed in a wide range of species. The bounds of the precursors are predicted based on conservation and base pairing and are not generally known.

mir-10 microRNA precursor family

The miR-10 microRNA precursor is a short non-coding RNA gene involved in gene regulation. It is part of an RNA gene family which contains miR-10, miR-51, miR-57, miR-99 and miR-100. miR-10, miR-99 and miR-100 have now been predicted or experimentally confirmed in a wide range of species. mir-51 and mir-57 have currently only been identified in the nematode Caenorhabditis elegans.

mir-156 microRNA precursor

MicroRNA (miRNA) precursor miR156 is a family of plant non-coding RNA. This microRNA has now been predicted or experimentally confirmed in a range of plant species. Animal miRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. In plants the precursor sequences may be longer, and the carpel factory (caf) enzyme appears to be involved in processing. In this case the mature sequence comes from the 5' arm of the precursor, and both Arabidopsis thaliana and rice genomes contain a number of related miRNA precursors which give rise to almost identical mature sequences. The extents of the hairpin precursors are not generally known and are estimated based on hairpin prediction. The products are thought to have regulatory roles through complementarity to mRNA.

mir-166 microRNA precursor

The plant mir-166 microRNA precursor is a small non-coding RNA gene. This microRNA (miRNA) has now been predicted or experimentally confirmed in a wide range of plant species. microRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. In this case the mature sequence comes from the 3' arm of the precursor, and both Arabidopsis thaliana and rice genomes contain a number of related miRNA precursors which give rise to almost identical mature sequences. The mature products are thought to have regulatory roles through complementarity to messenger RNA.

miR-218 microRNA precursor family

miR-218 microRNA precursor is a small non-coding RNA that regulates gene expression by antisense binding.

mir-29 microRNA precursor

The miR-29 microRNA precursor, or pre-miRNA, is a small RNA molecule in the shape of a stem-loop or hairpin. Each arm of the hairpin can be processed into one member of a closely related family of short non-coding RNAs that are involved in regulating gene expression. The processed, or "mature" products of the precursor molecule are known as microRNA (miRNA), and have been predicted or confirmed in a wide range of species.

mir-2 microRNA precursor

The mir-2 microRNA family includes the microRNA genes mir-2 and mir-13. Mir-2 is widespread in invertebrates, and it is the largest family of microRNAs in the model species Drosophila melanogaster. MicroRNAs from this family are produced from the 3' arm of the precursor hairpin. Leaman et al. showed that the miR-2 family regulates cell survival by translational repression of proapoptotic factors. Based on computational prediction of targets, a role in neural development and maintenance has been suggested.

mir-30 microRNA precursor

miR-30 microRNA precursor is a small non-coding RNA that regulates gene expression. Animal microRNAs are transcribed as pri-miRNA of varying length which in turns are processed in the nucleus by Drosha into ~70 nucleotide stem-loop precursor called pre-miRNA and subsequently processed by the Dicer enzyme to give a mature ~22 nucleotide product. In this case the mature sequence comes from both the 3' (miR-30) and 5' (mir-97-6) arms of the precursor. The products are thought to have regulatory roles through complementarity to mRNA.

The miR-34 microRNA precursor family are non-coding RNA molecules that, in mammals, give rise to three major mature miRNAs. The miR-34 family members were discovered computationally and later verified experimentally. The precursor miRNA stem-loop is processed in the cytoplasm of the cell, with the predominant miR-34 mature sequence excised from the 5' arm of the hairpin.

mir-7 microRNA precursor

This family represents the microRNA (miRNA) precursor mir-7. This miRNA has been predicted or experimentally confirmed in a wide range of species. miRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. In this case the mature sequence comes from the 5' arm of the precursor. The extents of the hairpin precursors are not generally known and are estimated based on hairpin prediction. The involvement of Dicer in miRNA processing suggests a relationship with the phenomenon of RNA interference.

mir-126

In molecular biology mir-126 is a short non-coding RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several pre- and post-transcription mechanisms.

miR-224

miR-224 is a family of microRNA precursors found in mammals, including humans. The ~22 nucleotide mature miRNA sequence is excised from the precursor hairpin by the enzyme Dicer.

miR-338

miR-338 is a family of brain-specific microRNA precursors found in mammals, including humans. The ~22 nucleotide mature miRNA sequence is excised from the precursor hairpin by the enzyme Dicer. This sequence then associates with RISC which effects RNA interference.

In molecular biology mir-11 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms. There is evidence to suggest that miR-11 plays a role in apoptosis.

In molecular biology mir-14 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.

References

  1. 1 2 3 Leaman D, Chen PY, Fak J, Yalcin A, Pearce M, Unnerstall U, Marks DS, Sander C, Tuschl T, Gaul U (July 2005). "Antisense-mediated depletion reveals essential and specific functions of microRNAs in Drosophila development". Cell. 121 (7): 1097–108. doi:10.1016/j.cell.2005.04.016. hdl: 11858/00-001M-0000-0012-EB54-F . PMID   15989958.
  2. ↑ Su H, Caldwell HD (January 1992). "Immunogenicity of a chimeric peptide corresponding to T helper and B cell epitopes of the Chlamydia trachomatis major outer membrane protein". The Journal of Experimental Medicine. 175 (1): 227–35. doi:10.1084/jem.175.1.227. PMC   2119084 . PMID   1370528.
  3. ↑ Figueiras AM, González-Jaén MT, Candela M, Benito C (2006). "Genic heterozygosity, chromosomal interchanges and fitness in rye: any relationship?". Genetica. 128 (1–3): 273–86. doi:10.1007/s10709-005-6242-2. PMID   17028957.

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