Figure 13.  Schematic representation of IL15Ra isoforms generated by alternate splicing

Isoform 1

[NM 008358]

This isoform is the full length IL15Ra chain shown to bind IL15

[Giri et al.]

Isoform 1A

Potential isoform identified in the present study lacking 33 amino acids at the beginning of the Pro/Thr-rich domain due to the splicing of exon 3 to a cryptic splice site in the middle of exon 4.

Isoform 1B

Potential isoform identified in the present study lacking 66 amino acids spanning the entire Pro/Thr-rich domain due to the splicing of exon 3 to exon 5, eliminating exon 4.

Isoform 1C

Potential isoform identified in the present study lacking 97 amino acids spanning most of the linker and the entire Pro/Thr-rich domain due to the splicing of exon 2 to exon 5, eliminating exons 3 and 4.

Isoform 2

[NM 133836]

Potential isoform identified by Giri et al. derived by splicing exon -1 to exon 2 and eliminating exon 1 resulting in the translational start site moving to exon 4 and a protein lacking the leader sequence, sushi domain, and linker domain.  The resulting polypeptide would presumably be confined to the cytoplasm.

mRNA

Leader sequence

"Sushi" domain

Linker domain

Pro/Thr rich domain

Transmembrane domain

Cytoplasmic domain