The loss of 40-kDa chromosomal protein in tuberous sclerosis lesions

Tuberous sclerosis is an genetic disease characterized by systemic hamartomas. Some of the cultured cells derived from tuberous sclerosis show the distinct chromosomal disarrangement and abnormal cell division. To detect the proteins responsible for this phenomenon, we investigated many nuclear components related to cell division. 40-kDa protein (p40) recognized by one monoclonal antibody M108, which was present in nucleus, chromosomes and cytoplasm of many vertebrate culture cells, significantly decreased in the tuberous sclerosis cells. Immunoblot analysis revealed that in all the fractions the quantity of p40 of severe tuberous sclerosis cells was approximately 4 times less than p40 in normal fibroblasts.