THE ALTERNATIVE SPLICING PATTERN OF THE TENASCIN-C PRE-MESSENGER-RNA IS CONTROLLED BY THE EXTRACELLULAR PH

Alternative splicing of primary transcripts is an ubiquitous and rever sible mechanism for the generation of multiple protein isoforms from s ingle genes, Here we report that in cultured normal human fibroblasts, small pH variations of the culture medium (from 7.2 to 6.9) strikingl y modify the alternative splicing pattern of the tenascin-C primary tr anscript. Since such extracellular pH variations occur in many normal and pathological conditions, microenvironmental pH may be an important element for the regulation of RNA alternative splicing in vivo.