Tissue- and Cell-Specific Alternative Splicing of <i>NFIC</i>

Abstract

Alternative splicing is an important mechanism for increasing genetic complexity leading to multiple transcripts from single genes and gene regulation through alternative promoters. Splicing often leads to unique tissue-specific patterns of mRNAs with specific biological functions. Nuclear factor I-C (NFI-C), a member of the NFI gene family, is expressed in numerous tissues including brain, liver, spleen and heart. However, the unique dental phenotype of Nfic^–/– mice lacking molar roots demonstrates a critical role for this transcription factor in root formation. In humans, the NFI-C gene is alternatively spliced producing 4 isoforms. However, different spliced variants have not been studied in association with tissue specificity. The main objective of this study is to identify the NFI-C isoforms expressed in dental cells/tissues, comparing them to the spliced variants in nondental cells/tissues and to analyze their relative expression levels in various cell types. Using bioinformatics, we analyzed the NFI-C gene structure, identifying 2 potential alternative promoters driving expression of selective mRNA transcripts. Our studies show the expression of 3 NFI-C transcripts with the overall splicing pattern conserved between dental and nondental cells tested. Furthermore, by quantitative real-time PCR analysis, we found that although the relative levels of these transcripts were similar in dental and nondental cells, significant differences were observed within the dental cells tested. These are the first studies to analyze the expression of NFI-C isoforms in dental versus nondental cells/tissues, finding subtle cell-/tissue-specific expression patterns that could explain the dental phenotype of Nfic^–/– mice.

Establishment of Singleton-Merten Syndrome pulp cells: evidence of mineralization dysregulation

“…Total RNA from cultured SMS and control pulp cells was isolated and converted to cDNA as previously outlined (2). Human osteogenesis RT 2 Profiler PCR Arrays (Qiagen, Valencia, CA) 96-well format plate, containing 84 genes related to osteogenic differentiation, were used following the supplier's manual (http://www.sabiosciences.com/rt_pcr_ product/HTML/PAHS-026Z.html).…”

Nuclear Janus-Activated Kinase 2/Nuclear Factor 1-C2 Suppresses Tumorigenesis and Epithelial-to-Mesenchymal Transition by Repressing Forkhead Box F1

“…The NF1 family consists of four genes (NF1-A, NF1-B, NF1-C, and NF1-X), each producing different splice variants, thereby generating a large number of protein isoforms. The expression levels of the different NF1 genes and the ratio between alternatively spliced transcripts vary between cell types and differentiation states (10)(11)(12)(13). In the mouse mammary gland, the specific isoform NF1-C2 is the dominating NF1-C protein and exhibits a characteristic temporal pattern during the adult developmental cycle; the mRNA is constitutively present, but the protein decreases during lactation to reemerge again at involution (9).…”

NFI‐C2 temporal‐spatial expression and cellular localization pattern during tooth formation

“…; Lamani et al . ). The mouse NFI‐C homology is mapped to chromosome 10 and similar C‐terminus variants to the human isoforms can be found in Ensembl (Flicek et al .…”

“…The mouse NFI-C homology is mapped to chromosome 10 and similar C-terminus variants to the human isoforms can be found in Ensembl (Flicek et al 2011). We have previously shown the NFI-C2 transcript to be the most abundant with high expression in both dental and nondental tissues, while NFI-C1 mRNA is present at very low quantities and NFI-C4 expression was only moderate (Lamani et al 2009). However, how this translates to the NFI-C protein levels during the various stages of tooth formation is yet to be determined.…”

“…NFIC, located on human chromosome 19p13.3, is encoded by 12 exons that are alternatively spliced producing three protein products: NFI-C1, NFI-C2, and NFI-C4 (Qian et al 1995;Lamani et al 2009). The mouse NFI-C homology is mapped to chromosome 10 and similar C-terminus variants to the human isoforms can be found in Ensembl (Flicek et al 2011).…”