Novel Proteomics Strategy Brings Insight into the Prevalence of SUMO-2 Target Sites

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Blomster HA, Hietakangas V, Wu JM, Kouvonen P, Hautaniemi S, Sistonen L
Förläggare: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Publiceringsår: 2009
Tidskrift: Molecular and Cellular Proteomics
Tidskriftsakronym: MOL CELL PROTEOMICS
Volym: 8
Nummer: 6
Artikelns första sida, sidnummer: 1382
Artikelns sista sida, sidnummer: 1390
Antal sidor: 9
ISSN: 1535-9476
eISSN: 1535-9484


Abstrakt

Small ubiquitin-like modifier (SUMO) is covalently conjugated to its target proteins thereby altering their activity. The mammalian SUMO protein family includes four members (SUMO-1-4) of which SUMO-2 and SUMO-3 are conjugated in a stress-inducible manner. The vast majority of known SUMO substrates are recognized by the single SUMO E2-conjugating enzyme Ubc9 binding to a consensus tetrapeptide (Psi KXE where Psi stands for a large hydrophobic amino acid) or extended motifs that contain phosphorylated or negatively charged amino acids called PDSM (phosphorylation-dependent sumoylation motif) and NDSM (negatively charged amino acid-dependent sumoylation motif), respectively. We identified 382 SUMO-2 targets using a novel method based on SUMO protease treatment that improves separation of SUMO substrates on SDS-PAGE before LC-ESI-MS/MS. We also implemented a software SUMOFI (SUMO motif finder) to facilitate identification of motifs for SUMO substrates from a user-provided set of proteins and to classify the substrates according to the type of SUMO-targeting consensus site. Surprisingly more than half of the substrates lacked any known consensus site, suggesting that numerous SUMO substrates are recognized by a yet unknown consensus site-independent mechanism. Gene ontology analysis revealed that substrates in distinct functional categories display strikingly different prevalences of NDSM sites. Given that different types of motifs are bound by Ubc9 using alternative mechanisms, our data suggest that the preference of SUMO-2 targeting mechanism depends on the biological function of the substrate.

Senast uppdaterad 2019-16-12 vid 03:36