N1-methyladenosine is a modified nucleoside in which a methyl group is added to N1 of the adenosine base. This modification introduces a positive charge on the nitrogen atom to which the methyl group is added, because the modified nitrogen donates its lone pair to the carbon atom of the methyl group in order to form a bond. N1-methyladenosine modification is thought to regulate tRNA and rRNA stability, as well as potentially alter protein-RNA interactions or RNA secondary structures. This modification results in the melting of double-stranded RNA, due to alterations in the RNA structure. The N1-methyladenosine modification is less common than the mA modification, with modified transcripts usually only containing a single mA modification, whereas they may contain several mA residues.
Studies of these modifications have been slow to advance due to a lack of sound methodology to locate and identify them. A few methods, such as MeRIP-seq and mA-ID-seq, have been developed, but the particular adenosine that is modified still cannot be identified. A computational tool based on the data generated from these methods called RAMPed has been developed to try to identify these particular modifications.
Disease
Modification of m1a is of interest regarding its considerable correlation with cancer biology and tumorigenesis.  Involvement of m1a may be organized under the categories of proliferation, invasion, cell death, tumor microenvironment, or cancer metabolism. Cancer cell proliferation has been found to be promoted by specific m1a “writers”. For example, the regulator TRMT6 has been found to be overexpressed in individuals with glioma, a cancer marked by the inappropriate proliferation of glial cells of the brain or spinal cord. Additionally, regulation of ALKBH3 has been found to support and bolster cancer cell invasiveness in certain breast and ovarian cancers.