Supplemental Material Supplementary Table 1 Primer extension and SS RT-PCR Leishmania infantum LSU γ 101-118 forward 5’-CCTTTTTACTTCTCGCGT-3’ Leishmania infantum LSU γ 1-22 forward 5’-TAGTGGTAATGCGAAACACTTG-3’ Leishmania infantum LSU γ 196-213 reverse 5’-ACACCCCAGGTTTTTGCT-3’ Leishmania infantum 18S rRNA 649-671 forward 5’-TATTAATGCTGTTGCTGTTAAAG-3’ Leishmania infantum 18S rRNA reverse (complementary to nucleotides 928-946) 5’-ACAAAAGCCGAAACGGTAG-3’ Leishmania infantum LSU α 1-21 forward 5’-ACAGACCTGAGTGTGGCAGGA-3’ Leishmania infantum LSU α reverse (complementary to nucleotides 245-266) 5’-CAATGGGCTAACACCTTCTTTG-3’ Leishmania infantum 5.8S 1-20 forward 5’-TATACAAAAGCAAAAATGTC-3’ Leishmania infantum 5.8S reverse (complementary to nucleotides 244-262) 5’-GTTCGACACTGAGAATATG-3’ Trypanosoma brucei LSU γ 1-20 forward 5’-ACTGTGGAAATGCGAAACAC-3’ Trypanosoma brucei LSU γ reverse (complementary to nucleotides 195-213) 5’-ACACCCCAGGTTTTTGCT-3’ Trypanosoma brucei LSU γ 101-118 forward 5’-GCCTCTCGACTTCTCGCG-3’ Human 28S rRNA forward (1-18 nt of 28S rRNA) 5’-CGCGACCTCAGATCAGAC-3’ Human 28S rRNA reverse (complementary to nucleotides 199-216 of the 28S rRNA) 5’-GGCCTCGATCAGAAGGAC-3’ 5’ and 3’ end mapping of sense and antisense LSU γ rRNAs Ambion adapter specific outer primer 5’-GCTGATGGCGATGAATGAACACTG-3’ Ambion adapter specific inner nested primer 5’CGCGGATCCGAACACTGCGTTTGCTGGCTTTGATG-3’ Oligo-dT primer 5’-CGGGATCCTTTTTTTTTTTTTTTTTT-3’ 1 Overexpression constructs Leishmania infantum LSU 1.2 forward 5’-GGTTAGGACGAAGCTTATG-3’ Leishmania infantum LSU 1.2 reverse 5’-CCCAAGCTTACTTGGATGCATCACAAAC-3’ LinHEL67 ORF forward 5’-GCTCTAGAATGTATAAGAATCAGGCGCAAC-3’ LinHEL67 ORF reverse 5’-CCAAGCTTCTACTGACCAAAGACGTCAGATCG-3’ Gene targeting constructs HYG targeting cassette Primers for amplification of the 5’flank region of the LinHEL67 gene 5’flank of HEL67 forward 5’-AGTATAGCAGGGATGGAGG-3’ 5’GGTGAGTTCAGGCTTTTTCATGATTCCTGCTTAGCAAACG-3’ 5’flank of HEL67 reverse Primers for hygromycin gene amplification HYG forward 5’-ATGAAAAAGCCTGAACTCACC-3’ HYG reverse 5’ACACGGAGTTTTACTACTCCATCTATTCCTTTGCCCTCGGAC GAG-3’ Primers for amplification of the 3’ flank region of the LinHEL67 gene 3’flank HEL67 forward 5’-ATGGAGTAGTAAAACTCCGTGT-3’ 5’-GACAGAGAAAAGCGTGTGTG-3’ 3’flank HEL67 reverse NEO targeting cassette Primers for amplification of the 5’flank region of the LinHEL67 gene 5’flank HEL67 forward 5’-AGTATAGCAGGGATGGAGG-3’ 5’-GGTGAGTTCAGGCTTTTTCATGATTCCTGCTTAGCAAACG-3’ 5’flank HEL67 reverse Primers for neomycin gene amplification NEO forward 5’-ATGATTGAACAAGATGGATTG-3’ NEO reverse 5’ACACGGAGTTTTACTACTCCATTCAGAAGAACTCGTCAAGA AG-3’ 2 Supplemental Figure Legends Supplemental Figure S1. Antisense RNA complementary to all ribosomal RNA species is naturally produced in Leishmania. (A) Single-stranded (SS)-RT-PCR was performed for both sense and antisense rRNA using reverse and forward primers, respectively (see Supplementary Table 1). The SS-cDNA was prepared using forward primers for antisense RNA and reverse primers for sense RNA against 18S rRNA (298 bp), 5.8S rRNA (262 bp) and LSU α (28S α) rRNA (266 bp). Arrow marks indicate amplified fragments obtained for respective sense and antisense RNA. -RT, cDNA was prepared without RT enzyme, (+), genomic DNA was used as a template for control. (B) Northern blot hybridization was carried out to detect antisense RNA complementary to each of the rRNAs mentioned above using single-stranded sense riboprobes. Supplemental Figure S2. Mapping of the ends of mature sense and antisense LSU γ rRNAs and derived fragments. (A) Pairwise sequence alignments of sLSU γ and asLSU γ rRNA complementary regions mapped by 5'-RACE to detect 5' ends and polyA polymerase strategy for detecting 3' ends. The sequence of six clones (three for the sense and three for the asLSU γ rRNA) is shown here. (B) Schematic diagram of complementary ends are depicted with arrow marks and doted lines. The solid line indicates the complementary ends and dotted lines indicate the fragments with one nucleotide overhang. Numbers 1, 57, 150, 213 indicate positions in the sLSU γ rRNA, and -1, -58, -151 and -213 positions in the asLSU γ RNA. Supplemental Figure S3. The 5′ ends of the sense LSU γ rRNA-derived fragments were mapped by 5′ RACE using Ambion RLM-5′ RACE kit. LSU γ rRNA fragments were aligned with the mature sense LSU γ rRNA (213 nt) by Clustalw method using Bioedit. A representative number of sequenced clones is shown here. 3 Supplemental Figure S4. (A, B upper panel) Leishmania lysates from unstressed (upper panel) and temperature (37°C)-stressed (bottom panel) promastigotes for 24 hrs were loaded onto linear 15-45% (w/w) sucrose gradient and fractionated by ultracentrifugation and by continuously recording absorbance at 254 nm. The small ribonuclear protein complexes (RNPs), 40S and 60S ribosomal subunits, 80S monosome and polysome peaks are indicated. (A, B bottom panels) Effect of temperature stress on sense (s) and antisense (as) LSU γ rRNA fragmentation. Total RNA extracted from unstressed and temperature-stressed L. infantum promastigotes was isolated from sucrose gradient fractions corresponding to RNPs (F1 to F2), 40S subunit (F3), 60S subunit (F4), 80S monosome (F5 and F6) and polysomes (F7 to F12), resolved on 10% urea-acrylamide gel and analyzed by northern blot hybridization with the 173 nt ss-DNA probe corresponding to nucleotides 41-213 of the sense LSU γ rRNA and recognizing the asLSU γ RNA or with the 5′end-labeled 42 nt oligonucleotide probe complementary to nucleotides 172-213 of the sense LSU γ rRNA (membrane exposure for 2 hrs). The northern blot data obtained with the unstressed parasites are also shown in Figure 1D and 1E but we have included them also here to facilitate direct comparisons. Sense and antisense LSU γ rRNA fragments are marked within a bracket and the mature sense and antisense LSU γ rRNAs are indicated with an arrow. Plain arrows indicate sense or antisense LSU γ rRNA fragments with a similar length between unstressed and heatstressed parasites. Open arrows indicate sense or antisense LSU γ rRNA fragments with a different length between unstressed and heat-stressed parasites corresponding most likely to new cleavage events. Supplemental Figure S5. High concentrations of cytotoxic but not apoptosis-inducing drugs failed to induce antisense LSU γ RNA fragmentation. (A) Primer extension analysis on total RNA of L. infantum amastigotes treated with high concentrations of G418 (125 µg/ml) and paramomycin sulphate (750 µg/ml) for 24 hrs using a primer corresponding to nucleotides 101118 of sLSU γ rRNA to detect asLSU γ cleavage products. Miltefosine (MF)-treated samples were used as a positive control for the induction of asLSU γ RNA fragmentation. The size of cleavage fragments was compared with an end-labeled ΦX174 DNA/HinfI dephosphorylated DNA marker (Promega) (M). (B) Primer extension analysis as described in A but using a primer complementary to nucleotides 96-213 of sLSU rRNA to detect sLSU γ rRNA cleavage 4 products. MF-treated samples were used as a positive control for the induction of sLSU γ rRNA degradation. Supplemental Figure S6. Effect of miltefosine treatment on general translation in Leishmania. Representative A254 nm polysome profiling analysis of 15% to 45% sucrose density ultracentrifugation of L. infantum untreated (A) and miltefosine (MF: 40 µM)-treated promastigotes (B) for 24 h. The 40S and 60S ribosomal subunits, 80S monosome and polysome peaks are indicated. The MF treatment leads to the disappearance of ribosomal peaks and translation inhibition due to the induction of apoptosis. Supplemental Figure S7. LSU rRNA degradation appears generally at the same time interval than antisense LSU RNA fragmentation. Log-phase L. infantum amastigotes (OD 0.4) were treated with MF 20 µM for 1 to 8 h. The RNA was isolated by Trizol and used for primer extension analysis to detect both asLSU γ RNA fragmentation (A) (forward primer corresponding to nucleotides 101-118 of LSU γ rRNA; see Supplementary Table 1) and sense LSU γ rRNA degradation (B) (reverse primer complementary to nucleotides 196-213 of LSU γ rRNA; see Supplementary Table 1). Supplemental Figure S8. MS/MS analysis of proteins bound to both the sense and antisense LSU γ rRNAs as determined by UV-crosslinking. The mass-spectrometry (MS/MS) results of UV-crosslinked proteins bound to the sense LSU γ rRNA analyzed by Scaffold 3. An ATPdependent RNA helicase of 67 kDa encoded by LinJ.32.0410 gene (TriTrypDB; http://tritrypdb.org) (previous systematic name was LinJ32_V3.0770), which belongs to a highly conserved subfamily of DEAD-box helicases, is shown in blue box with a solid arrow mark. Supplemental Figure S9. Sequence alignment of the Leishmania ATP-dependent DEAD-box helicase HEL67 with homologues from other eukaryotes. Sequence comparison of L. infantum HEL67 with corresponding homologues using ClustalW2. The ClustalW2 aligned sequences were used for box shade by BOXSHADE 3.21 program. The L. infantum HEL67 sequence was compared with the C. elegans Vbh-1 homologue, Saccharomyces cerevisiae Ded1 homologue, DEAD-box protein homologue of Drosophila melanogaster (VASA), Mus musculus VASA 5 homologue, and Neurospora crassa CYT-19 homologue. Identical amino acids in all sequences are shaded in black. Black bar underlined regions have DEAD-box conserved amino acids. ATPase A motif (AXTGXGKT) is marked by a red bar, SAT region (critical role unwinding helicase action) is marked by a blue bar and the region involved in ATP hydrolysis is underlined by a green bar. Gaps denoted by dashes have been introduced into the output by ClustalW in order to align the sequences. 6