Biology:Mir-802 microRNA precursor family

mir-802
Identifiers
Symbol	mir-802
Rfam	RF00887
miRBase family	MIPF0000353
Other data
RNA type	microRNA
Domain(s)	Eukaryota;
PDB structures	PDBe

In molecular biology mir-802 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.

ROMK Channels and Caveolin-1 Suppression

miR-802 expression in the kidney is stimulated by a high potassium intake, along with caveolin-1 expression, one of the many miR-802 protein targets. Surface expression of Renal Outer Medullary Potassium (ROMK) channels has been found to be enhanced in the plasma membrane of the distal nephron of the kidney by miR-802 expression. Caveolin-1 conversely inhibits ROMK channel activity, and expression of the two shows a clear inverse relationship. Co-expression of miR-802 with caveolin-1 blocks miR-802's upregulatory effects on ROMK channels. miR-802 thus functions to mediate the stimulatory effect of a high potassium diet on ROMK activity through suppression of caveolin-1 expression, this leading to an increased surface expression of ROMK channels.

Human Chromosome 21

Human chromosome 21 (Hsa21) has been found to harbour over 400 different genes, with miR-802 among these. Along with miRNAs-99a, -125b-2, -155 and let-7c, miR-802 is overexpressed in brain and heart specimens of Down syndrome individuals, resulting in suppression of specific target proteins. This suppression in turn contributes towards the common phenotypic alterations observed in Down syndrome patients.

See also

• MicroRNA

Further reading

• Keck-Wherley, J.; Grover, D.; Bhattacharyya, S.; Xu, X.; Holman, D.; Lombardini, E. D.; Verma, R.; Biswas, R. et al. (2011). "Abnormal MicroRNA Expression in Ts65Dn Hippocampus and Whole Blood: Contributions to Down Syndrome Phenotypes". Developmental Neuroscience 33 (5): 451–467. doi:10.1159/000330884. PMID 22042248. 
• Lin, D. -H.; Yue, P.; Pan, C.; Sun, P.; Wang, W. -H. (2011). "MicroRNA 802 Stimulates ROMK Channels by Suppressing Caveolin-1". Journal of the American Society of Nephrology 22 (6): 1087–1098. doi:10.1681/ASN.2010090927. PMID 21566059. 
• Rand, V.; Parker, H.; Russell, L. J.; Schwab, C.; Ensor, H.; Irving, J.; Jones, L.; Masic, D. et al. (2011). "Genomic characterization implicates iAMP21 as a likely primary genetic event in childhood B-cell precursor acute lymphoblastic leukemia". Blood 117 (25): 6848–6855. doi:10.1182/blood-2011-01-329961. PMID 21527530. 
• Elton, T. S.; Sansom, S. E.; Martin, M. M. (2010). "Trisomy-21 gene dosage over-expression of miRNAs results in the haploinsufficiency of specific target proteins". RNA Biology 7 (5): 540–547. doi:10.4161/rna.7.5.12685. PMID 21081842. 
• Sansom, S. E.; Nuovo, G. J.; Martin, M. M.; Kotha, S. R.; Parinandi, N. L.; Elton, T. S. (2010). "MiR-802 regulates human angiotensin II type 1 receptor expression in intestinal epithelial C2BBe1 cells". AJP: Gastrointestinal and Liver Physiology 299 (3): G632–G642. doi:10.1152/ajpgi.00120.2010. PMID 20558762. 
• Zhang, Y. J.; He, X. J.; Liu, Y. J.; Zhang, Q. (2010). "Abnormal expression of microRNAs in the hippocampus of Ts65Dn mice". Beijing da Xue Xue Bao. Yi Xue Ban = Journal of Peking University. Health Sciences 42 (2): 173–178. PMID 20396359. 
• Kuhn, D. E.; Nuovo, G. J.; Terry Jr, A. V.; Martin, M. M.; Malana, G. E.; Sansom, S. E.; Pleister, A. P.; Beck, W. D. et al. (2009). "Chromosome 21-derived MicroRNAs Provide an Etiological Basis for Aberrant Protein Expression in Human Down Syndrome Brains". Journal of Biological Chemistry 285 (2): 1529–1543. doi:10.1074/jbc.M109.033407. PMID 19897480. 
• Kuhn, D. E.; Nuovo, G. J.; Martin, M. M.; Malana, G. E.; Pleister, A. P.; Jiang, J.; Schmittgen, T. D.; Terry Jr, A. V. et al. (2008). "Human chromosome 21-derived miRNAs are overexpressed in down syndrome brains and hearts". Biochemical and Biophysical Research Communications 370 (3): 473–477. doi:10.1016/j.bbrc.2008.03.120. PMID 18387358. 

External links

• Page for mir-802 microRNA precursor family at Rfam