miR-30 microRNA precursor is a small
non-coding RNA
A non-coding RNA (ncRNA) is a functional RNA molecule that is not translated into a protein. The DNA sequence from which a functional non-coding RNA is transcribed is often called an RNA gene. Abundant and functionally important types of non-c ...
that regulates
gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. The ...
. Animal
microRNA
MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miRN ...
s are transcribed as pri-miRNA (primary miRNA) of varying length which in turns are processed in the nucleus by Drosha into ~70
nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules wi ...
stem-loop
Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when ...
precursor called pre-miRNA (precursor miRNA) and subsequently processed by the
Dicer
Dicer, also known as endoribonuclease Dicer or helicase with RNase motif, is an enzyme that in humans is encoded by the gene. Being part of the RNase III family, Dicer cleaves double-stranded RNA (dsRNA) and pre-microRNA (pre-miRNA) into short d ...
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.
A screen of 17 miRNAs that have been predicted to regulate a number of
breast cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...
associated genes found variations in the microRNAs
miR-17 and miR-30c-1, these patients were noncarriers of
BRCA1
Breast cancer type 1 susceptibility protein is a protein that in humans is encoded by the ''BRCA1'' () gene. Orthologs are common in other vertebrate species, whereas invertebrate genomes may encode a more distantly related gene. ''BRCA1'' is a h ...
or
BRCA2
''BRCA2'' and BRCA2 () are a human gene and its protein product, respectively. The official symbol (BRCA2, italic for the gene, nonitalic for the protein) and the official name (originally breast cancer 2; currently BRCA2, DNA repair associated) ...
mutations, lending the possibility that familial breast cancer may be caused by variation in these miRNAs.
Members of the miR-30 family have been found to be highly expressed in heart cells.
Targets of miR-30
It has been shown that the integrin
ITGB3
Integrin beta-3 (β3) or CD61 is a protein that in humans is encoded by the ''ITGB3'' gene. CD61 is a cluster of differentiation found on thrombocytes.
Structure and function
The ITGB3 protein product is the integrin beta chain beta 3. Integrins ...
and the ubiquitin conjugating E2 enzyme
UBC9
SUMO-conjugating enzyme UBC9 is an enzyme that in humans is encoded by the ''UBE2I'' gene. It is also sometimes referred to as "ubiquitin conjugating enzyme E2I" or "ubiquitin carrier protein 9", even though these names do not accurately describe ...
are downregulated by miR-30. It has also been suggested that the
TP53
p53, also known as Tumor protein P53, cellular tumor antigen p53 (UniProt name), or transformation-related protein 53 (TRP53) is a regulatory protein that is often mutated in human cancers. The p53 proteins (originally thought to be, and often s ...
protein may be a target of miR-30c and miR-30e. An immunoblot analysis revealed that p53 expression levels were elevated upon knockdown of miR-30c and miR-30e.
References
Further reading
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External links
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MicroRNA
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