Differential roles of RNA binding proteins hnRNP L and LL in hormone production in rat pituitary cells

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Lei, Lei
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OBJECTIVES: The role of heterogeneous nuclear ribonucleoproteins in controlling hormone production is not well-understood. This study aims to determine the regulatory roles of hnRNP L and LL in hormone production. RESULTS: HnRNP LL knockdown dramatically reduced the mRNA level of growth hormone (GH) and prolactin (PRL) in GH3 pituitary cells, which was efficiently rescued by a Myc-hnRNP LL. In contrast, hnRNP L knockdown caused a 93-nucleotide intron retention with a decrease in the full-length Prl, which was rescued by a FLAG-hnRNP L. Double knockdown of hnRNPs indicates the interactions of hnRNPs for particular effects. The essential role of hnRNP LL for the secretion of GH and PRL was verified in primary pituitary cultures. Using RNA sequencing, a group of genes in hormone production that were differentially regulated by hnRNP L or LL were identified. CONCLUSION: These findings demonstrate the differential functions of two paralogous RNA processing factors in hormone production.
Endocrine, Hormones, RNA, Splicing, Processing, Gene regulation, Gene expression, Molecular biology