Concerted effects of heterogeneous nuclear ribonucleoprotein C1/C2 to control vitamin D-directed gene transcription and RNA splicing in human bone cells

Research output: Contribution to journalArticlepeer-review

Authors

  • Rui Zhou
  • Juw Won Park
  • Rene Chun
  • Thomas Lisse
  • Alejandro J Garcia
  • Kathryn Zavala
  • Jessica Sea
  • Zhi-xiang Lu
  • Jianzhong Xu
  • John Adams
  • Yi Xing

Colleges, School and Institutes

External organisations

  • UCLA Orthoped Hosp
  • University of California
  • The Jackson Laboratory, Bar Harbor, ME 04609, USA
  • Department of Orthopaedics, The Orthopedic Surgery Center of Chinese PLA, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China

Abstract

Traditionally recognized as an RNA splicing regulator, heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNPC1/C2) can also bind to double-stranded DNA and function in trans as a vitamin D response element (VDRE)-binding protein. As such, hnRNPC1/C2 may couple transcription induced by the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D) with subsequent RNA splicing. In MG63 osteoblastic cells, increased expression of the 1,25(OH)2D target gene CYP24A1 involved immunoprecipitation of hnRNPC1/C2 with CYP24A1 chromatin and RNA. Knockdown of hnRNPC1/C2 suppressed expression of CYP24A1, but also increased expression of an exon 10-skipped CYP24A1 splice variant; in a minigene model the latter was attenuated by a functional VDRE in the CYP24A1 promoter. In genome-wide analyses, knockdown of hnRNPC1/C2 resulted in 3500 differentially expressed genes and 2232 differentially spliced genes, with significant commonality between groups. 1,25(OH)2D induced 324 differentially expressed genes, with 187 also observed following hnRNPC1/C2 knockdown, and a further 168 unique to hnRNPC1/C2 knockdown. However, 1,25(OH)2D induced only 10 differentially spliced genes, with no overlap with differentially expressed genes. These data indicate that hnRNPC1/C2 binds to both DNA and RNA and influences both gene expression and RNA splicing, but these actions do not appear to be linked through 1,25(OH)2D-mediated induction of transcription.

Details

Original languageEnglish
Pages (from-to)606–618
Number of pages13
JournalNucleic Acids Research
Volume45
Issue number2
Early online date26 Sep 2016
Publication statusPublished - Jan 2017