Organization and chromosomal localization of the human interleukin 5 receptor alpha-chain gene.
The gene for the hIL-5R alpha subunit, which is present in a single copy in the human genome, has been analysed in detail. It is located on chromosome 3 in the region 3p26. The gene organization reflects its relationship to the cytokine/haematopoietin receptor superfamily. Three introns are located in the 5' untranslated region. The subsequent exons determine the functional domains of the hIL-5R alpha protein: the signal peptide, three fibronectin type III-like (FN-like) modules, each built up by two exons, the membrane anchor and two exons forming the cytoplasmic tail, the first of which contains the proline cluster region. In addition, a specific exon generating a soluble isoform is located before the membrane anchor exon. This specific exon contains an in frame TAA stop codon, followed by a polyadenylation signal. Hence, a normal splicing event leads to a soluble IL-5R alpha variant, whereas alternative splicing is required for cell membrane anchoring. A second area of alternative splicing is found in the 5' leader sequence, and possibly relates to the presence of short open reading frames preceding the main ATG. All intron-exon junctions meet the GT-AG rule. The gene structures of all cytokine/haematopoietin receptors documented so far have also been compared with respect to intron phasing. This shows that all introns between the FN-III-like modules are of the +1 type, but in addition, splice sites within the Cys-module and WS-WS-module are invariably of the +2 and 0 type, respectively.
Tuypens
T
T
Roche Research Gent, Belgium.
Plaetinck
G
G
Baker
E
E
Sutherland
G
G
Brusselle
G
G
Fiers
W
W
Devos
R
R
Tavernier
J
J
D000595:Amino Acid Sequence; D001483:Base Sequence; D002874:Chromosome Mapping; D002893:Chromosomes, Human, Pair 3; D005091:Exons; D005796:Genes; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D012322:RNA Precursors / Q000235:genetics; D012326:RNA Splicing; D011971:Receptors, Immunologic / Q000235:genetics*; D018123:Receptors, Interleukin; D053649:Receptors, Interleukin-5
D012322:RNA Precursors; D011971:Receptors, Immunologic; D018123:Receptors, Interleukin; D053649:Receptors, Interleukin-5