Microprocessor complex
| Ribonuclease III | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 1374 amino acids | |
| Cofactor | Mg 2+ | |
| Isoforms | 3 | |
| Identifier | ||
| Gene name | RNASES | |
| External IDs | ||
| Enzyme classification | ||
| EC, category | 3.1.26.3 , hydrolase | |
| Substrate | Double stranded RNA + H 2 O | |
| Products | 5'-phosphoroligonuclotides | |
| Occurrence | ||
| Homology family | Drosha | |
| Parent taxon | Bilateral animals | |
| Orthologue | ||
| human | House mouse | |
| Entrez | 29102 | 14000 |
| Ensemble | ENSG00000113360 | ENSMUSG00000022191 |
| UniProt | Q9NRR4 | Q5HZJ0 |
| Refseq (mRNA) | NM_001100412 | NM_001130149 |
| Refseq (protein) | NP_001093882 | NP_001123621 |
| Gene locus | Chr 5: 31.4 - 31.53 Mb | Chr 15: 12.82 - 12.94 Mb |
| PubMed search | 29102 |
14000
|
| Protein DGCR8 | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 773 amino acids | |
| Isoforms | 3 | |
| Identifier | ||
| Gene name | DGCR8 | |
| External IDs | ||
| Occurrence | ||
| Homology family | DGCR8 | |
| Parent taxon | Euteleostomi | |
| Orthologue | ||
| human | House mouse | |
| Entrez | 54487 | 94223 |
| Ensemble | ENSG00000128191 | ENSMUSG00000022718 |
| UniProt | Q8WYQ5 | Q9EQM6 |
| Refseq (mRNA) | NM_001190326 | NM_033324 |
| Refseq (protein) | NP_001177255 | NP_201581 |
| Gene locus | Chr 22: 08/20 - 11/20 Mb | Chr 16: 18.25 - 18.29 Mb |
| PubMed search | 54487 |
94223
|
The microprocessor complex is an enzyme complex in the cell nucleus and processes the primary transcript pri- miRNA into pre- miRNA. The enzyme complex consists of the RNA binding protein Pasha (DGCR8) and the RNase III Drosha .
The primary transcript is the nucleus of located there genes by polymerase II transcribed . Drosha and Pasha play an important role in the processing of the primary transcript.
Pasha binds the pri-miRNA with a length of 500 to 3000 nucleotides to stabilize it for processing by Drosha.
Drosha shows only weak and unspecific RNAse activity, but gains selectivity and efficiency through Pasha and can cleave the primary transcript into the pre-miRNA of about 70 nucleotides in length.
After processing by the microprocessor complex, the pre-miRNA with a length of about 70 nucleotides accumulates to form a hairpin structure and can reach the cytoplasm through active transport .
Hundreds of different miRNAs exist in plants and animals. miRNAs regulate cell metabolism and differentiation by regulating the translation of mRNAs . This happens through more or less exact binding of the miRNAs to the mRNAs. Depending on how exactly the miRNA binds to the mRNA, i.e. how complementary the base pairing is, the more effectively the translation and thus the expression with regard to the protein for which the respective mRNA codes.
Individual evidence
- ↑ Y. Lee, among others: MicroRNA genes are transcribed by polymerase II. In: EMBO J . 23 (20), 2004, pp. 4051-4060. PMID 15372072 doi: 10.1038 / sj.emboj.7600491
- ^ Y. Zeng et al .: Recognition and cleavage of primary microRNA precursors by the nuclear processing enzyme Drosha. In: EMBO J. 24 (1), 2005, pp. 138-148. PMID 15565168 doi: 10.1038 / sj.emboj.7600385