Specific enrichment of the RNA-binding proteins PCBP1 and PCBP2 in chief cells of the murine gastric mucosa

• PCBP1 and PCBP2 co-localize within the gastric glandular epithelium.
• PCBP1/2 are specifically enriched in chief cells.
• PCBP1/2 are found in the nucleus and cytoplasm of chief cells.
• PCBP1/2 are nucleus restricted in the parietal cell lineage.
• PCBP1/2 expression correlates with gastric gland elongation in the post-natal period.

RNA-binding proteins and corresponding post-transcriptional controls play critical roles in gene expression. The poly-(C) binding proteins, PCBPs (αCPs, hnRNPEs), comprise a well-characterized family of abundant RNA-binding proteins that impact on RNA processing in the nucleus as well as mRNA stability and translation in the cytoplasm. Here we demonstrate that PCBP1 and PCBP2 are abundantly expressed in the gastric epithelium with prominent enrichment in specific cell types within the gastric glandular mucosa. The spatial and intracellular patterns of PCBP1 and PCBP2 expression in these regions are highly correlated. Remarkably, we observe that these proteins are present in the nuclear and cytoplasmic compartments of zymogenic chief cells while they are restricted to the nuclear compartment in acid-secreting parietal cells and poorly expressed in pit cells that line the gland exit. This specificity of expression patterns and subcellular localization of PCBP1 and PCBP2, along with their appearance in the precursor tissues of the gastric epithelium during early postnatal development, suggests these RNA-binding proteins play specific roles in cell differentiation and organismal development within the gastric glandular epithelium.