This gene encodes a protein that is a member of the SUMO (small ubiquitin-like modifier) protein family. It is a ubiquitin-like protein and functions in a manner similar to ubiquitin in that it is bound to target proteins as part of a post-translational modification system. However, unlike ubiquitin, which is primarily associated with targeting proteins for proteasomal degradation, SUMO2 is involved in a variety of cellular processes, such as nuclear transport, transcriptional regulation, apoptosis, and protein stability. It is not active until the last two amino acids of the carboxy-terminus have been cleaved off. Numerous pseudogenes have been reported for this gene. Alternate transcriptional splice variants encoding different isoforms have been characterized.[6]
Deep hypothermia protects the brain from ischemic injury, which is why it's employed for major cardiovascular procedures that necessitate cardiopulmonary bypass and a period of circulatory arrest. With an experiment [9] conducted to moderate hypothermia, small ubiquitin-like modifier (SUMO1-3) conjugation was significantly activated in the brain. The effects of hypothermia on SUMO conjugation were evaluated in this experiment[9] using Western blot and immunohistochemistry in animals that were either normothermic (37 °C) or deep to moderate (18 °C, 24 °C, 30 °C) hypothermic cardiopulmonary bypass. In these cells, even 30 °C hypothermia was enough to significantly boost SUMO2/3-conjugated protein levels and nucleus accumulation. Deep hypothermia caused the SUMO-conjugating enzyme Ubc9 to translocate to the nucleus, implying that the increase in nuclear levels of SUMO2/3-conjugated proteins seen in hypothermic animals' brains is an active process. Deep hypothermia caused only a small increase in the amounts of SUMO2/3-conjugated proteins in primary neuronal cells. This shows that neurons in vivo have a greater capacity to activate this endogenous possibly neuroprotective mechanism when exposed to hypothermia than neurons in vitro. Identifying proteins that are SUMO2/3 conjugated during hypothermia could aid in the development of new preventive and therapeutic therapies to make neurons more resistant to a transient blood supply interruption.
^Golebiowski F, Matic I, Tatham MH, Cole C, Yin Y, Nakamura A, Cox J, Barton GJ, Mann M, Hay RT (2009). "System-wide changes to SUMO modifications in response to heat shock". Science Signaling. 2 (72): ra24. doi:10.1126/scisignal.2000282. PMID19471022. S2CID33450256.
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Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano S (Oct 1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene. 200 (1–2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID9373149.
Su HL, Li SS (Aug 2002). "Molecular features of human ubiquitin-like SUMO genes and their encoded proteins". Gene. 296 (1–2): 65–73. doi:10.1016/S0378-1119(02)00843-0. PMID12383504.
Tatham MH, Kim S, Yu B, Jaffray E, Song J, Zheng J, Rodriguez MS, Hay RT, Chen Y (Aug 2003). "Role of an N-terminal site of Ubc9 in SUMO-1, -2, and -3 binding and conjugation". Biochemistry. 42 (33): 9959–69. doi:10.1021/bi0345283. PMID12924945.
