Fig. 1.

STAiR18 is duplicated in the human genome and expressed like an mRNA. a Schematic representation of duplicated STAiR18 on chromosome 2 with the LINC00152 locus on the plus and the MIR4435-2HG locus on the minus strand. b Transcripts derived from the LINC00152 (STAiR18-A) and MIR4435-2HG (STAiR18-B) loci show different exonic patterns. The duplication comprises 200 kb of the 5ˈ-region containing exon 1–4 of STAiR18, exons 5–9 are unique (hg19). c Locus-specific expression of STAiR18 in IL-6-treated or withdrawn INA-6 cells measured by qPCR using either locus-specific primers (STAiR18-A and STAiR18-B) or a primer pair detecting transcripts from both loci. Values were normalized to U6 RNA (n = 3). d Determination of STAiR18 copy number per cell. A serial dilution of pcDNA plasmid containing STAiR18 and reverse transcribed RNA from 1 × 10⁴ INA-6 cells were subjected to qPCR using the STAiR18 (both) primer pair. A logarithmic regression was added, enabling the determination of STAiR18 copy number by Ct value (n = 3). e Determination of STAiR18 Half-Life (HL) by treating INA-6 cells with ActinomycinD (ActD) for indicated durations, followed by RNA isolation, RT and qPCR using intron-spanning primers for STAiR18, STAT3 and U6. Values were adjusted to U6 RNA and normalized to the DMSO control (n = 3). HL was determined by a polynomic regression