LRDD, a novel leucine rich repeat and death domain containing protein

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.