The 90 kDa heat shock protein (hsp90) family of proteins that play an important physiological role. Hsp90
is involved in numerous cellular processes but is best
known for its association with signal transduction
machinery. A recently cloned homolog of hsp90 is the
tumor necrosis factor receptor-associated protein
(TRAP1). Like hsp90, TRAP1 is found to be associated with
numerous proteins involved in diverse actions (1, 2).
Immunofluorescence data has shown TRAP1 to be
localized in the mitochondria of mammalian cells.
This observation and the fact that TRAP1 is shown to have
a mitochondrial targeting pre-sequence strongly implicates
TRAP1 as a mitochondrial matrix protein (3).