Identification and functional analysis of growth rate associated long non-coding RNAs in Komagataella phaffii

Long non-coding RNAs (lncRNAs) are a regulatory feature that have been reported to operate on both transcriptional and translational levels. With DNA-based prediction still limited, lncRNAs are most reliably identified through genome-guided mapping of RNA-Seq data. Reports of lncRNAs in yeast have been increasing in recent years and changes in their expression levels have often been associated with stressful conditions. As the transition to near zero-growth conditions likely imposes stress, we used RNA-Seq data from the non-conventional, biotechnologically established yeast Komagataella phaffii, cultivated in glucose-limited retentostats, to identify the expression of lncRNAs. Using an adapted bioinformatics pipeline, we identified 168 mostly novel lncRNAs from the K. phaffii retentostat RNA-Seq data, 36 of which demonstrate likely growth-associated expression changes. lncRNA expression levels were associated to that of possible interaction partners, in both cis and trans, suggesting potential roles in regulatory adaptations. Our analysis indicates that lncRNAs likely contribute to how K. phaffii responds to changing environmental conditions, as exemplified here by the adaptation to extremely slow growth.