An interolog is a conserved interaction between a pair of proteins which have interacting homologs in another organism. The term was introduced in a 2000 paper by Walhout et al.
Example
Suppose that A and B are two different interacting human proteins, and A' and B' are two different interacting dog proteins. Then the interaction between A and B is an interolog of the interaction between A' and B' if the following conditions all hold: A is a homolog of A'. (Protein homologs have similar amino acid sequences and derive from a common ancestral sequence). B is a homolog of B'. A and B interact. A' and B' interact.
Thus, interologs are homologous pairs of protein interactions across different organisms.
See also Homology (biology) Systems biology Bioinformatics
References
External links Interactome.org : Interactome portal site. : Interactomics portal site. : Cross-species interaction prediction site.