N-end rule

The N-end rule is a rule that governs the rate of protein degradation through recognition of the N-terminal residue of proteins. The rule states that the N-terminal amino acid of a protein determines its half-life (likelihood of being degraded). The rule applies to both eukaryotic and prokaryotic organisms, but with different strength, rules, and outcome. In eukaryotic cells, these N-terminal residues are recognized by N-degrons that are targeted by ubiquitin ligases, mediating ubiquitination thereby marking the protein for degradation. The rule was initially discovered by Alexander Varshavsky and co-workers in 1986. However, only rough estimations of protein half-life can be deduced from this 'rule', as N-terminal amino acid modification can lead to variability and anomalies, whilst amino acid impact can also change from organism to organism. Other degradation signals, known as degrons, can also be found in sequence. The N-end rule is a rule that governs the rate of protein degradation through recognition of the N-terminal residue of proteins. The rule states that the N-terminal amino acid of a protein determines its half-life (likelihood of being degraded). The rule applies to both eukaryotic and prokaryotic organisms, but with different strength, rules, and outcome. In eukaryotic cells, these N-terminal residues are recognized by N-degrons that are targeted by ubiquitin ligases, mediating ubiquitination thereby marking the protein for degradation. The rule was initially discovered by Alexander Varshavsky and co-workers in 1986. However, only rough estimations of protein half-life can be deduced from this 'rule', as N-terminal amino acid modification can lead to variability and anomalies, whilst amino acid impact can also change from organism to organism. Other degradation signals, known as degrons, can also be found in sequence.