2238
Although polyubiquitin chains linked through Lys ( 29 ) of ubiquitin have been implicated in the targeting of certain substrates to proteasomes , the signaling properties of these chains are poorly understood .
 GENE: polyubiquitin chains; GENE: ubiquitin
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: polyubiquitin chains; GENE: ubiquitin