NO link to destruction

杨柳

Cysteine was already known to be destabilizing when present as an NH2-terminal residue, and there were hints that its oxidation might be involved. The Caltech group now find that oxidation is essential to make the cysteine a substrate for arginyl transferase. The arginylated protein is then destroyed by the rest of the N-end rule pathway.+ Z' a' c  w( g# |
  u! |, {* x7 s1 o3 e2 I
One substrate of this pathway is shown to be the GTPase-activating protein RGS4. It is no longer arginylated and is more abundant in vivo when either arginyl transferase is deleted or NO levels are reduced pharmacologically. Two other RGS proteins are also substrates, and 30 uncharacterized proteins are candidates.
9 y0 B1 s$ T& e( c; w3 q- s& b5 }2 P
NO's short half-life, says Varshavsky, gives you the possibility of regulating proteins through on a subcellular level. NO-related drugs for regulating blood vessels and heart function may become more specific if they could be targeted to the N-end rule's part of NO signaling.
4 `; D. \; D: j: Y: i( v6 _
' E, c$ F  t& dReference:1 Z" [" n) R! }) M  @. e4 c* r% e

: d" H1 O' |  z( ~  t5 wHu, R.-G., et al. 2005. Nature. doi:10.1038/nature04027.(Two domains of cell behavior—protein mod)