Cell Biologist with EMBO-sponsored postdoctoral training in US. Research experience in Israel, US, Canada. Trying to understand the mechanisms of intracellular and extracellular cell signaling and communication, functions of multi-protein signaling complexes, protein-protein interactions and post-translational protein modifications (PTMs), using genetically tractable eukaryotic models, (ex., Dicty) and other conventional genetics models up to humans. Especially interested to investigate the identities and activities of the enzymes catalyzing certain PTMs at signaling proteins (Tyrosine Phosphorylation, SUMOylation, Ubiquitination). Discovered and characterized the first founding member of SUMO-targeted Ubiquitin Ligase (StUBL) family of proteins. Recently got interested in applying Genome Editing and Targeted Protein Degradation (TPD) approaches to the problems of cell biology. I would like to study the biological functions of PTMs, how specific mutations and Sequence Polymorphisms (SNPs) affect PTMs, composition of multi-protein signaling complexes, localization and activities.I apply tools of molecular genetics and cell biology to address these questions. 

Саша, декабрь 1971 года.jpeg

Me - 1971

Лея Ихилевна Зильберштейн (Левковская).j

My grandmother

Leah Zilberstein


Cover image Dev Cell.jpg
  • We discovered that upon chemoattractant stimulation, DdMEK1 is SUMOylated and interacts with C3HC4-type RING finger protein MIP. SUMOylation controls DdMEK1 nuclear export and localization in the actin-enriched cell cortex, where it activates ERK1. MIP ubiquitinates DdMEK1 and controls its nuclear localization (Sobko A, Ma H, Firtel RA, Dev Cell, 2002)

  • S. pombe Aurora-like kinase Arc1 interacts with Rfp1 and Rfp2. Rfp1 interacts with Pmt3, the fission yeast SUMO homologue (Sun H, Leverson JD, Hunter T., EMBO J. 2007)

  • Dictyostelium MIP, S. pombe Rfp1/Rfp2 and mammalian RNF4 have N-terminal SUMO-interactive motifs and C-terminal RING finger domains and belong to SUMO-targeted Ubiquitin Ligases (StUbl) family of proteins.





1999 - 2003

University of California, San Diego

EMBO Postdoctoral Fellowship - SUMOylation and Ubiquitination of DdMEK1, MIP1 - DdMEK1-associated SUMO-targeted Ubiquitin Ligase



Protein-protein interactions


Protein kinase localization and activity


1995 - 1999

The Weizmann Institute of Science, Dept. of Neurobiology


1991 - 1994

The Hebrew University of Jerusalem, Dept. of Neurobiology

M.Sc. with distinction