CTD Small Phosphatase 1 (CTDSP1)

CTDSP1 contains putative regulatory elements including consensus binding sequences for Sp1, AP2, NF-kappa-B, and PU1. Analysis of the predicted amino acid sequence suggested to the authors that NLIIF is a cytoplasmic protein that may be translocated to the nucleus. Northern blot analysis revealed ubiquitous expression of a 2.6-kb NLIIF mRNA in all tissues tested, with highest expression in spleen, lung, and placenta. A second mRNA of approximately 7 kb was expressed only in placenta.The phosphatase domain of CTDSP1 shares more than 90% homology with the phosphatase domains of CTDSP2 and CTDSPL, and about 20% homology with the phosphatase domain of CTDP1. Immunofluorescence microscopy localized endogenous CTDSP1 in the nucleus of COS-7 cells.