Figure 1

Identification of a novel truncated FR4 variant from BALB/c mouse splenocytes. (A) Schematic diagram of the mouse FR4 gene. Exons are indicated by solid lines, and introns by dashed lines. Positions of primers used for PCR amplification are shown by arrows. (B) RT-PCR detection of full-length CDS of FR4 and FR4D3 genes in mouse splenocytes. (C) RT-PCR detection of FR4 and FR4D3 mRNA in splenocytes, CD4⁺ T cells, and CD4⁺CD25⁺ T cells. (D) The nucleotide and predicted amino acid sequences of the novel mouse FR4D3 CDS. The 189 bp exon 3 was deleted and did not cause frame shift mutation. The exons are indicated in bold and the exon-exon junction sites are indicated by arrows. (E) Western blotting assay showing FR4 and FR4D3 proteins detected by rat anti-mouse FR4 monoclonal antibody (mAb). Here, 50 μg splenocyte lysates were treated with N-glycosidase before blotting[15].