TitleA genome-wide search of Toll/Interleukin-1 receptor (TIR) domain-containing adapter molecule (TICAM) and their evolutionary divergence from other TIR domain containing proteins.
Publication TypeJournal Article
Year of Publication2022
AuthorsVerma S, Sowdhamini R
JournalBiol Direct
Date Published2022 Sep 02
KeywordsAdaptor Proteins, Vesicular Transport, Receptors, Interleukin-1, Signal Transduction, Toll-Like Receptors

Toll/Interleukin-1 receptor (TIR) domains are cytoplasmic domain that mediates receptor signalling. These domains are present in proteins like Toll-like receptors (TLR), its signaling adaptors and Interleukins, that form a major part of the immune system. These TIR domain containing signaling adaptors binds to the TLRs and interacts with their TIR domains for downstream signaling. We have examined the evolutionary divergence across the tree of life of two of these TIR domain containing adaptor molecules (TICAM) i.e., TIR domain-containing adapter-inducing interferon-β (TRIF/TICAM1) and TIR domain containing adaptor molecule2 (TRAM/TICAM2), by using computational approaches. We studied their orthologs, domain architecture, conserved motifs, and amino acid variations. Our study also adds a timeframe to infer the duplication of TICAM protein from Leptocardii and later divergence into TICAM1/TRIF and TICAM2/TRAM. More evidence of TRIF proteins was seen, but the absence of conserved co-existing domains such as TRIF-NTD, TIR, and RHIM domains in distant relatives hints on diversification and adaptation to different biological functions. TRAM was lost in Actinopteri and has conserved domain architecture of TIR across species except in Aves. An additional isoform of TRAM, TAG (TRAM adaptor with the GOLD domain), could be identified in species in the Mesozoic era. Finally, the Hypothesis based Likelihood ratio test was applied to look for selection pressure amongst orthologues of TRIF and TRAM to search for positively selected sites. These residues were mostly seen in the non-structural region of the proteins. Overall, this study unravels evolutionary information on the adaptors TRAM and TRIF and how well they had duplicated to perform diverse functions by changes in their domain architecture across lineages.

Alternate JournalBiol Direct
PubMed ID36056415
PubMed Central IDPMC9440496
Grant ListSB/S2/JC-071/2015 / / Science and Engineering Research Board, India /
BT/PR40187/BTIS/137/9/2021 / / Department of Biotechnology, India /
IBAB/MSCB/182/2022 KMS Computational Biology Chair / / Institute of Bioinformatics and Applied Biotechnology /