Beyond proteins: Ubiquitylation of lipopolysaccharide to fight bacteria.

Mechanisms and functions of protein ubiquitylation and LPS ubiquitylation. LPS ubiquitylation serves as a scaffold to recruit E3 ligases for the ubiquitylation of the membrane of bacteria. Polyubiquitin coat on the bacterial cell surface is one type of "eat-me" signal recognized by the host cells. The abbreviations used in the figure are Pro, Protein; Ub, Ubiquitin; E1, Ubiquitin-activating enzymes; E2, Ubiquitin-conjugating enzymes; E3, Ubiquitin-ligating enzymes; LPS, lipopolysaccharide; RNF213, Ring Finger Protein 213; and LUBAC, linear ubiquitin chain assembly complex.