SEQUENCE-SPECIFIC AND LENGTH-DEPENDENT INTERACTION OF C2H2 ZINC FINGERS AND (TA)(N) MICROSATELLITES

A possible function for microsatellite elements still remains elusive. Here we demonstrate that (TA)(n) microsatellites can be recognized in vivo in transient assays by a combination of naturally occurring C2H2 zinc fingers with high affinity that depends on specific protein-DNA contacts. This interaction results in an upregulation of the basal tra nscription level, when (TA)(n) elements are placed upstream of a minim al promoter. Upregulation depends on the length of the element. Our re sults suggest that specific interaction of transcription factors with microsatellite sequences may underlie effects on transcriptional regul ation exerted by these sequences. Identification of such interactions would be a first step towards understanding the function and evolution of microsatellite elements.