Question

You have discovered that a particular mRNA of GeneX in maize is required for the regulation of GeneY. However, this mRNA does not encode any proteins, yet in its absence the levels of protein Y (product of GeneY) are significantly increased. Propose one likely mechanism for how GeneX may be controlling the levels of Protein Y.

Answer 1

mRNA of geneX in maize is a non-coding RNA. A non coding mRNA is transcribed from DNA and is functional but it does not get translated into a protein. This non coding mRNA of geneX binds to the complementary sequence that is present on geneY mRNA. As a result geneY mRNA undergoes cleavage or degradation. This results in the blocking of translation of geneY mRNA. As a result the levels of protein Y are absent in presence of geneX mRNA.

In the absence of geneX mRNA, geneY mRNA is not cleaved or degraded. As a result geneY mRNA is translated and this results in significantly increased levels of gene Y protein in the absence of geneX mRNA.