Death domains (DD) and leucine rich repeats (LRR) are two different types o
f protein interaction motifs. Death domains are found predominantly in prot
eins involved in signaling and are involved in homo- and heteromultimerizat
ion. Leucine rich repeats are found in proteins with diverse cellular funct
ions, like cell adhesion and cellular signaling, and mediate reversible pro
tein-protein interactions. In this paper we report the cloning of a new hum
an gene called LRDD (leucine repeat death domain containing protein). LRDD
encodes a protein of 83 kDa with six LRRs at the N-terminus and a DD at the
C-terminus. LRDD appears to be processed into two fragments of about 33 an
d 55 kDa, containing LRRs and DD respectively. Interestingly, LRDD is shown
to interact with two other death domain containing proteins, FADD and MADD
, presumably through death domain interactions. LRDD may represent a new ty
pe of adapter protein that could be involved in signaling or other cellular
functions. (C) 2000 Elsevier Science B.V. All rights reserved.