A high throughput mutagenic analysis of yeast sumo structure and function.
Sumoylation regulates a wide range of essential cellular functions through diverse mechanisms that remain to be fully understood. Using S. cerevisiae, a model organism with a single essential SUMO gene (SMT3), we developed a library of >250 mutant strains with single or multiple amino acid substitutions of surface or core residues in the Smt3 protein. By screening this library using plate-based assays, we have generated a comprehensive structure-function based map of Smt3, revealing essential amino acid residues and residues critical for function under a variety of genotoxic and proteotoxic stress conditions. Functionally important residues mapped to surfaces affecting Smt3 precursor processing and deconjugation from protein substrates, covalent conjugation to protein substrates, and non-covalent interactions with E3 ligases and downstream effector proteins containing SUMO-interacting motifs. Lysine residues potentially involved in formation of polymeric chains were also investigated, revealing critical roles for polymeric chains, but redundancy in specific chain linkages. Collectively, our findings provide important insights into the molecular basis of signaling through sumoylation. Moreover, the library of Smt3 mutants represents a valuable resource for further exploring the functions of sumoylation in cellular stress response and other SUMO-dependent pathways.
Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America.
Heather A
HA
Newman
High Throughput Biology Center and Department of Molecular Biology and Genetics, Johns Hopkins University, School of Medicine, Baltimore, MD, United States of America.
Pamela B
0000-0002-2792-2297
PB
Meluh
Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America.
Jian
J
Lu
Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America.
Jeremy
0000-0001-9005-9521
J
Vidal
Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America.
Caryn
C
Carson
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America.
Elizabeth
0000-0003-0713-0812
E
Lagesse
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America.
Jeffrey J
0000-0001-6380-2324
JJ
Gray
High Throughput Biology Center and Department of Molecular Biology and Genetics, Johns Hopkins University, School of Medicine, Baltimore, MD, United States of America.
Jef D
JD
Boeke
Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America.
Michael J
0000-0002-9350-6611
MJ
Matunis
D019943:Amino Acid Substitution / Q000235:genetics; D004252:DNA Mutational Analysis; D016296:Mutagenesis / Q000235:genetics; D009153:Mutagens / Q000633:toxicity; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics*; D013329:Structure-Activity Relationship; D058207:Sumoylation / Q000187:drug effects*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics
D009153:Mutagens; C099362:SMT3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; D044767:Ubiquitin-Protein Ligases