How do lncRNAs act as miRNA decoys/sponges? Do they only bind to the miRNA seed sequence or can they act by binding to other parts of the miRNA as well? Is it possible for lncRNA to act at precursor miRNA level?
Hi. You can use programs such as LncTar to predict whether your miRNA and lncRNA would interact (based on sequence homily and thermodynamics) or any of these prediction programs: Ingenuity Pathway Analysis (http://www.ingenuity.com/ ), microRNA.org (http://www.microrna.org/microrna/home.do) and MicroCosm (http://www.ebi.ac.uk/enright-srv/microcosm/htdocs/targets/v5/ ) - however I am unsure if they will accept the lncRNA as input sequence. And yes, lncRNAs can be precursors of miRNAs (see paper by Noon et al. 2014 [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4163095/]) - which also explains how the sponge effect works.