Physiol. Genomics 12: 47-51, 2002.
First published October 29, 2002; doi:10.1152/physiolgenomics.00073.2002
1094-8341/02 $5.00
Received 11 June 2002;
accepted in final form 25 October 2002.
Physiological Genomics 12:47-51 (2002)
1094-8341/02 $5.00 © 2002 American Physiological Society
Exon truncation by alternative splicing of murine ICAM-1
Joseph P. Mizgerd,
Matt R. Spieker and
Michal M. Lupa
Physiology Program, Harvard School of Public Health, Boston, Massachusetts 02115
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.
lungs; neutrophils; pneumonia; integrins; immunoglobulins
