Characterization of the membrane-bound and a soluble form of human IL-4 receptor alpha produced by alternative splicing.
IL-4 plays a major role in IgE production. Its signal is conferred to effector cells through binding to the alpha chain of the membrane-bound human IL-4 receptor (huIL-4Ralpha). Here we present the genomic structure and organization of huIL-4Ralpha. The promotor region shows binding sites for several transcription factors involved in inflammatory processes. HuIL-4Ralpha has been shown to be organized differently to that of mouse IL-4Ralpha. A soluble form of huIL-4Ralpha is produced by alternative splicing of the huIL-4Ralpha gene (shuIL-4Ralpha/splice). Expression of the corresponding mRNA coding for the extracellular part of the receptor and an additional three amino acids is also shown. A second form of huIL-4Ralpha, i.e. shuIL-4Ralpha/prot, is produced by limited proteolysis of the receptor (shedding) and is already known. These results reveal a complex pattern for the regulation of the IL-4 pathway at the receptor level. The patterns of expression of all three receptor proteins as well as their individual meaning in the context of inflammation still have to be elucidated.
Kruse
S
S
University Children's Hospital, University of Freiburg, Mathildenstrasse 1, 79106 Freiburg, Germany.
Forster
J
J
Kuehr
J
J
Deichmann
K A
KA
D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D005091:Exons; D006801:Humans; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D019948:Receptors, Interleukin-4 / Q000096:biosynthesis / Q000235:genetics*
D019948:Receptors, Interleukin-4