SUMMARYIn plant organelles, RNA editing alters specific cytidine residues to uridine in transcripts. Target cytidines are specifically recognized by pentatricopeptide repeat (PPR) proteins of the PLS subfamily, which have additional C-terminal E or E-DYW motifs. Recent in silico analysis proposed a model for site recognition by PLS-subfamily PPR proteins, with a correspondence of one PPR motif to one nucleotide, and with the C-terminal last S motif aligning with the nucleotide at position -4 with respect to the editing site. Here, we present quantitative biochemical data on site recognition by four PLS-subfamily proteins: CRR28 and OTP85 are DYW-class members, whereas CRR21 and OTP80 are E-class members. The minimal RNA segments required for high-affinity binding by these PPR proteins were experimentally determined. The results were generally consistent with the in silico-based model; however, we clarified that several PPR motifs, including the C-terminal L2 and S motifs of CRR21 and OTP80, are dispensable for the RNA binding, suggesting distinct contributions of each PPR motif to site recognition. We also demonstrate that the DYW motif interacts with the target C and its 5 0 proximal region (from À3 to 0), whereas the E motif is not involved in binding.

The present study investigated which cognitive characteristics, including cancer phobia, self-efficacy, pain-related catastrophizing, and anxiety sensitivity, affect burning mouth syndrome (BMS) symptoms in the Japanese population. A total of 46 BMS patients (44 women and 2 men; mean age, 59.98 +/- 9.57 years; range, 30-79 years) completed a battery of questionnaires, including measures of pain severity, oral-related quality of life (QOL), stress-response, pain-related catastrophizing, self-efficacy, anxiety sensitivity, and tongue cancer phobia. The Pain Catastrophizing Scale (PCS), General Self-Efficacy Scale (GSES), and Anxiety Sensitivity Index (ASI) scores in the BMS patients were compared with the scores of Japanese healthy participants (PCS, n = 449; GSES, n = 278; ASI, n = 9603) reported in previous studies. Catastrophizing and anxiety sensitivity were significantly higher in the BMS patients than in the healthy subjects (P < 0.001). In BMS patients, catastrophizing was significantly correlated with pain severity, stress-response, psychological disability, social disability, and handicap. Cancer phobia was significantly correlated with psychological disability and handicap. Since catastrophizing showed a higher correlation with BMS symptoms than cancer phobia, catastrophizing might be a more significant cognitive factor affecting symptoms than cancer phobia in BMS patients in the Japanese population.