miR-338 is a family of brain-specific microRNA precursors found in mammals, including humans.[1] The ~22 nucleotide mature miRNA sequence is excised from the precursor hairpin by the enzyme Dicer.[2] This sequence then associates with RISC which effects RNA interference.[3]
miR-338 is located in an intronic region within the gene for apoptosis-associated tyrosine kinase (AATK). It has been predicted that it may downregulate genes which have a downstream negative effect on AATK expression.[4]
Function
miR-338 is a brain-specific miRNA which regulates the expression of cytochrome c oxidase IV (COX4).[1][5] The mature miR-338 miRNA sequence is complementary to a short section of the 3' untranslated region of COX4 mRNA. This mRNA sequence is presented atop a stem-loop structure, indicating it is accessible to miRNA processing.[5]
Applications
miR-338 is dysregulated in neuroblastoma, and could potentially be implemented as a biomarker or future therapeutic agent.[6] miR-338 has also been linked with hepatocellular carcinoma, and a large-scale diagnostic test has been suggested involving measurement of miR-338 expression in tissue samples.[7] Furthermore, miR-338 is one of seven microRNAs whose expression profiles can be combined to give a prediction of the probability of survival of a patient with gastric cancer.[8]
^ abKaplan BB, Gioio AE, Hillefors M, Aschrafi A (2009). "Axonal protein synthesis and the regulation of local mitochondrial function". Cell Biology of the Axon. Results and Problems in Cell Differentiation. Vol. 48. pp. 225–42. doi:10.1007/400_2009_1. ISBN978-3-642-03018-5. PMC2786086. PMID19343315.
^Ragusa M, Majorana A, Banelli B, Barbagallo D, Statello L, Casciano I, Guglielmino MR, Duro LR, Scalia M, Magro G, Di Pietro C, Romani M, Purrello M (Oct 2010). "MIR152, MIR200B, and MIR338, human positional and functional neuroblastoma candidates, are involved in neuroblast differentiation and apoptosis". Journal of Molecular Medicine. 88 (10): 1041–53. doi:10.1007/s00109-010-0643-0. PMID20574809. S2CID22215883.
He QY, Peng GP, Liu WX, Luo BY (Nov 2010). "[Interaction of microRNA-338 and its potential targeting protein eiF4E3]". Zhejiang da Xue Xue Bao. Yi Xue Ban = Journal of Zhejiang University. Medical Sciences. 39 (6): 583–8. doi:10.3785/j.issn.1008-9292.2010.06.006. PMID21166051. (Chinese)