Type 2 methionine aminopeptidase (MetAP2) is the molecular target for the fumagillin inhibitors against angiogenesis. Making use of the yeast two-hybrid system with GAL4 DBD-fused MetAP2 as a bait, a human brain cDNA library was screened to isolate protein factors that might interact with MetAP2. Among the 2x10(6) transformants obtained, five positive clones were picked out. Sequence analysis revealed that three of them contained cDNA fragments from flotillin and encode a carboxy terminus (starting from amino acids 145--233, respectively) of flotillin protein. The interaction between MetAP2 and flotillin detected by yeast two-hybrid system suggests that MetAP2 might play a role in some biological processes where flotillin is involved.