Poly(A)-binding proteins are highly conserved among eukaryotes and regulate stability of mRNA and translation. Among C. elegans homologues,
pab-1 mutants showed defects in germline mitotic proliferation. Unlike
pab-1 mutants,
pab-1 RNAi at every larval stage caused arrest of germline development at the following stage, indicating that
pab-1 is required for the entire postembryonic germline development. This idea is supported by the observations that the mRNA level of
pab-1 increased throughout postembryonic development and its protein expression was germline-enriched. PAB-1 localized to P granules and the cytoplasm in the germline. PAB-1 colocalized with CGH-1 and CAR-1 and affected their localization, suggesting that PAB-1 is a component of processing (P)-bodies that interacts with them. The mRNA and protein levels of representative germline genes,
rec-8, GLP-1,
rme-2, and
msp-152, were decreased after
pab-1 RNAi. Although the mRNA level of
msp-152 was increased in
cgh-1 mutant, it was also significantly reduced by
pab-1 RNAi. Our results suggest that PAB-1 positively regulates the mRNA levels of germline genes, which is likely facilitated by the interaction of PAB-1 with other P-body components, CGH-1 and CAR-1.