Sumoylation regulates nuclear localization of repressor DREAM.
DREAM is a Ca(2+)-binding protein with specific functions in different cell compartments. In the nucleus, DREAM acts as a transcriptional repressor, although the mechanism that controls its nuclear localization is unknown. Yeast two-hybrid assay revealed the interaction between DREAM and the SUMO-conjugating enzyme Ubc9 and bioinformatic analysis identified four sumoylation-susceptible sites in the DREAM sequence. Single K-to-R mutations at positions K26 and K90 prevented in vitro sumoylation of recombinant DREAM. DREAM sumoylation mutants retained the ability to bind to the DRE sequence but showed reduced nuclear localization and failed to regulate DRE-dependent transcription. In PC12 cells, sumoylated DREAM is present exclusively in the nucleus and neuronal differentiation induced nuclear accumulation of sumoylated DREAM. In fully differentiated trigeminal neurons, DREAM and SUMO-1 colocalized in nuclear domains associated with transcription. Our results show that sumoylation regulates the nuclear localization of DREAM in differentiated neurons. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
Centro Nacional de Biotecnología, CSIC, Madrid, Spain.
Malgorzata
M
Palczewska
Iñigo
I
Casafont
Kedar
K
Ghimire
Ana M
AM
Rojas
Alfonso
A
Valencia
Miguel
M
Lafarga
Britt
B
Mellström
Jose R
JR
Naranjo
D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism*; D004252:DNA Mutational Analysis; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D051605:Kv Channel-Interacting Proteins / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D016716:PC12 Cells; D011485:Protein Binding; D021381:Protein Transport; D051381:Rats; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism*; D025842:SUMO-1 Protein / Q000378:metabolism; D016415:Sequence Alignment; D058207:Sumoylation; D014276:Trigeminal Nerve / Q000378:metabolism / Q000648:ultrastructure; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism; D000098843:Ubiquitin-Conjugating Enzyme UBC9
C496756:Csen protein, mouse; C496760:Kcnip3 protein, rat; D051605:Kv Channel-Interacting Proteins; D050505:Mutant Proteins; D012097:Repressor Proteins; D025842:SUMO-1 Protein; D044763:Ubiquitin-Conjugating Enzymes; D000098843:Ubiquitin-Conjugating Enzyme UBC9