Correction: The purine nucleoside phosphorylase pnp-1 regulates epithelial cell resistance to infection in C. elegans.

[This corrects the article DOI: 10.1371/journal.ppat.1009350.].

After publication of this article, the authors noted an error in the amino acid change predicted for the pnp-1(jy90) mutant allele. The mutant allele is incorrectly annotated as Leucine throughout the text. The wild-type codon is TCC, which codes for the amino acid Serine, and the correct jy90 mutant allele is TTC, which codes for the amino acid Phenylalanine. The PLOS Pathogens editors have confirmed that this error does not affect the conclusions of the study.

Fig 1 is incorrect due to the error described above. The authors have provided a corrected version here.

Fig 1

pnp-1 mutants have increased expression of IPR genes.

A) Gene structure of the two isoforms of pnp-1 with exons indicated as black boxes. 5’ and 3’ untranslated regions are not shown. B-D) pals-5p::gfp IPR reporter expression in wild-type animals, pnp-1(jy90) and pnp-1(jy121) mutants. myo-2p::mCherry is a pharyngeal marker for the presence of the IPR reporter transgene. Scale bar is 100 μm. E) qRT-PCR of a subset of IPR genes in pnp-1(jy90) and pnp-1(jy121) mutants. Fold change in gene expression is shown relative to wild-type animals. Graph shows the mean fold change of three independent experiments. Error bars are standard deviation (SD). Mixed stage populations of animals were used. **** indicates p < 0.0001 by one-tailed t-test. F) Quantification of inosine and hypoxanthine levels in pnp-1 and pals-22 mutants from metabolomics analysis. Graph shows the mean levels of metabolites from six independent experiments for pnp-1(jy121), pnp-1(jy90) and pals-22(jy1) mutants, and five independent experiments for wild-type animals. Error bars are standard error of the mean (SEM). ** indicates p < 0.01 by the Kruskal-Wallis test. E, F) Red dots indicate values from individual experiments. See materials and methods for more information.

In the pnp-1 is a negative regulator of IPR gene expression subsection of the Results, there is an error in the fourth sentence of the first paragraph. The correct sentence is: From this analysis, we identified a missense mutation in the PNP gene pnp-1, which should result in substitution of a conserved serine (S51 or S68 in isoform a or b, respectively) to phenylalanine.

There is an error in the sixth sentence of the fifth paragraph of the Discussion. The correct sentence is: Support for the model that the catalytic activity of pnp-1 is required for its effects on the IPR comes from the pnp-1(jy90) allele, which has a conserved serine mutated to phenylalanine.

In the Forward mutagenesis screening and cloning of pnp-1(jy90) subsection of the Methods, there is an error in the last sentence of the first paragraph. The correct sentence is: pnp-1(jy90) contains a G to A substitution that should convert serine 51 to phenylalanine in isoform A and serine 68 to phenylalanine in isoform B.