The implications of telomerase biochemistry for human disease.

The replication of linear chromosome termini (telomeres) cannot be completely replicated by conventional DNA polymerases. Telomerase is a special DNA polymerase used by most eukaryotes to solve the telomere and replication problem. Telomerase is necessary for indefinite cell division in most immortal cells, but apparently unnecessary for the normal function of most somatic tissues. Telomerase may play a critical role in some genetic diseases, in regulating the lifespan of normal cells, and in tumorigenesis. This article reviews the structure and reaction mechanism of mammalian telomerase and how it may be exploited to control some human diseases.