The alternative splicing pattern of the tenascin-C pre-mRNA is controlled by the extracellular pH.

Alternative splicing of primary transcripts is an ubiquitous and reversible mechanism for the generation of multiple protein isoforms from single genes. Here we report that in cultured normal human fibroblasts, small pH variations of the culture medium (from 7.2 to 6.9) strikingly modify the alternative splicing pattern of the tenascin-C primary transcript. 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.