RESUMEN
Peptide nucleic acid (PNA) based antisense strategy is a promising therapeutic approach to specifically inhibit target gene expression. However, unlike protein coding genes, identification of an ideal PNA binding site for non-coding RNA is not straightforward. Here, we compare the inhibitory activities of PNA molecules that bind a non-coding 4.5S RNA called SRP RNA, a key component of the bacterial signal recognition particle (SRP). A 9-mer PNA (PNA9) complementary to the tetraloop region of the RNA was more potent in inhibiting its interaction with the SRP protein, compared to an 8-mer PNA (PNA8) targeting a stem-loop. PNA9, which contained a homo-pyrimidine sequence could form a triplex with the complementary stretch of RNA inâ vitro as confirmed using a fluorescent derivative of PNA9 (F-PNA13). The RNA-PNA complex formation resulted in inhibition of SRP function with PNA9 and F-PNA13, but not PNA8 highlighting the importance of target site selection. Surprisingly, F-PNA13 which was more potent in inhibiting SRP function inâ vitro, showed weaker antibacterial activity compared to PNA9 likely due to poor cell penetration of the longer PNA. Our results underscore the importance of suitable target site selection and optimum PNA length to develop better antisense molecules against non-coding RNA.
Asunto(s)
Ácidos Nucleicos de Péptidos , Ácidos Nucleicos de Péptidos/química , Ácidos Nucleicos de Péptidos/farmacología , Ácidos Nucleicos de Péptidos/metabolismo , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Sitios de Unión , ARN no Traducido/genética , ARN no Traducido/química , ARN no Traducido/metabolismo , Partícula de Reconocimiento de Señal/metabolismo , Partícula de Reconocimiento de Señal/química , Partícula de Reconocimiento de Señal/genética , ARN Bacteriano/química , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , Secuencia de Bases , Conformación de Ácido NucleicoRESUMEN
Antibiotic resistance has emerged as a global threat due to the ability of bacteria to quickly evolve in response to the selection pressure induced by anti-infective drugs. Thus, there is an urgent need to develop new antibiotics against resistant bacteria. In this review, we discuss pathways involving bacterial protein biogenesis as attractive antibacterial targets since many of them are essential for bacterial survival and virulence. We discuss the structural understanding of various components associated with bacterial protein biogenesis, which in turn can be utilized for rational antibiotic design. We highlight efforts made towards developing inhibitors of these pathways with insights into future possibilities and challenges. We also briefly discuss other potential targets related to protein biogenesis.
Asunto(s)
Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Proteínas Bacterianas/antagonistas & inhibidores , Antibacterianos/síntesis química , Antibacterianos/química , Bacterias/metabolismo , Proteínas Bacterianas/metabolismo , Farmacorresistencia Bacteriana/efectos de los fármacos , Modelos Moleculares , Estructura MolecularRESUMEN
We have identified the bacterial signal recognition particle (SRP) as a novel antibacterial target. As a proof of principle, we used an antisense peptide nucleic acid to target a key SRP RNA. The PNA molecules showed efficient inhibition of SRP function and bacterial cell growth, thereby validating our hypothesis.
