
AsianScientist (Apr. 30, 2014) – A team of scientists based in Taiwan has discovered that ubiquitin polymerization at lysine 33 functions in protein trafficking. The research was published in the journal Molecular Cell.
Ubiquitin is a small molecule made up of 76 amino acids, including seven lysines: K6, K11, K27, K29, K33, K48 and K63. The lysines serve as points of ubiquitination, a process where ubiquitin molecules are joined to proteins. While ubiquitination at K48 and K63 is relatively well-understood, ubiquitination at other lysine residues can result in different cellular functions which have not been characterized. The research, led by Academia Sinica Distinguished Research Fellow Dr. Chen Ruey-Hwa, is the first to unravel the function of ubiquitination at K33.
The team found that the enzyme Cul3-KLHL20 ubiquitin E3 ligase adds ubiquitin chains via K33 linkages to the protein coronin 7. This targets coronin 7 to a subcellular location known as the trans Golgi network.
Many physiological processes, such as hormone secretion, immune responses and neural transmission, are closely related to the transport of cell materials out of a cellular organelle called the Golgi apparatus. Understanding how cells target proteins to the trans Golgi network could shed light on these processes.
The article can be found at: Yuan et al. (2014) K33-Linked Polyubiquitination of Coronin 7 by Cul3-KLHL20 Ubiquitin E3 Ligase Regulates Protein Trafficking.
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Source: Academia Sinica; Photo: net_efekt/Flickr/CC.
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