Activation of the human immunodeficiency virus type 1 enhancer is not dependent on NFAT-1. 
The function of a putative NFAT-1 site in the human immunodeficiency virus type 1 enhancer has been analyzed. Activation by the T-cell antigen receptor is minimal in Jurkat cells and is mediated by the kappa B sites. The putative NFAT-1 region is not required for the response to anti-CD3 or to mitogens in T-cell, B-cell, or monocyte/macrophage leukemia lines, nor is it a cis-acting negative regulatory element.