Exon truncation by alternative splicing of murine ICAM-1.
The murine gene for intercellular adhesion molecule-1 (ICAM-1) encodes multiple products, arising from alternative splicing. Full-length ICAM-1 contains five extracellular Ig domains, each encoded by a separate exon. Alternatively spliced forms have Ig domains 2, 3, and/or 4 excised as a result of exon skipping. We report here a novel splice variant of murine ICAM-1, resulting from exon truncation rather than exon skipping and affecting Ig domain 5. A 5' splice donor site within exon 6 generates transcripts missing 69 nucleic acids from the 3' terminus of the exon. This in-frame exon truncation is predicted to replace 24 amino acids within Ig domain 5 with a single aspartic acid residue, yielding a structure other than an Ig domain immediately external to the membrane. Expression of this alternatively spliced form is induced in mouse lungs, spleen, and kidneys during LPS-induced pulmonary inflammation. Since the affected region is critical for ICAM-1 presentation, dimerization, and solubilization, this alternative splice variant may have unique physiological functions.
Mizgerd
Joseph P
JP
Physiology Program, Harvard School of Public Health, Boston, Massachusetts 02115, USA. jmizgerd@hsph.harvard.edu
Spieker
Matt R
MR
Lupa
Michal M
MM
D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D005091:Exons; D007136:Immunoglobulins / Q000737:chemistry; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D008168:Lung / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011014:Pneumonia / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D017434:Protein Structure, Tertiary; D022821:RNA Splice Sites; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D007136:Immunoglobulins; D020033:Protein Isoforms; D022821:RNA Splice Sites; D018799:Intercellular Adhesion Molecule-1