Malignant T-Cell Amplified Sequence 1 (MCTS1)

MCT1 protein was not detected in leukemic cells from patients with chronic lymphocytic leukemia or in any healthy lymphoid tissue examined. Lymphoid cell lines overexpressing MCT1 exhibited increased growth and were protected from serum starvation-induced apoptosis. MCT1-overexpressing cells showed constitutively higher levels of phosphorylated AKT protein, especially under serum starvation.

The deduced 181-amino acid protein has a calculated molecular mass of 20 kD. MCT1 has 4 phosphorylation sites and a 58-amino acid C-terminal domain similar to the protein-protein interaction domain of cyclin H (CCNH). Northern blot analysis detected low ubiquitous expression of an MCT1 transcript smaller than 1 kb.