LYMPHOCYTE-SPECIFIC INDUCIBLE EXPRESSION OF POTASSIUM CHANNEL BETA-SUBUNITS

Many studies have shown that voltage-gated potassium (Kv) channel acti vity is essential for T-lymphocyte proliferation. The IL-2-inducible n euroimmune gene, 12rf5 is the mouse homologue of the rat Kv beta 2 sub unit. In this study we show that in addition to constitutive expressio n in adult murine brain, expression of Kv channel subunits beta 1.1 an d beta 2.1 is inducible in a cloned T-helper cell line stimulated with IL-2 and in normal murine splenocytes stimulated with Con A or LPS. T his expression pattern appears to be lymphocyte specific, because stim ulated fibroblasts and vascular smooth muscle cells do not express Kv beta channel subunit mRNA. These observations suggest that Kv beta sub unit expression is tissue specific and inducible in stimulated lymphoc ytes. Because Kv beta subunits modulate K+ channel activity, the induc ible and variable expression of these subunits in lymphocytes may repr esent an additional regulatory mechanism for lymphocyte proliferation.