{"title":"鸟嘌呤核苷酸交换因子和链起始因子2对真核细胞蛋白质合成的调控。","authors":"L P Singh, A J Wahba","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>In eukaryotes, the guanine nucleotide exchange factor (eIF-2B) is a key protein in the control of polypeptide chain initiation. It catalyzes the exchange of chain initiation factor (eIF)-2-bound GDP for GTP and facilitates the formation of a ternary complex (eIF-2.GTP.Met-tRNAf). The activity of eIF-2B is inhibited indirectly by phosphorylation of the smallest subunit of eIF-2 which sequesters eIF-2B into an inactive eIF-2(alpha P).eIF-2B complex. On the other hand, eIF-2B activity may be regulated directly by covalent modification of its largest subunit with different kinases, such as casein kinase (CK)-I, CK-II and glycogen synthase kinase (GSK)-3. After stimulation of mammalian cells by insulin or growth factors, the allosteric activation of eIF-2B activity by sugar phosphates and inositol phosphates may also provide an important parameter in the regulation of protein synthesis.</p>","PeriodicalId":77373,"journal":{"name":"SAAS bulletin, biochemistry and biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Regulation of protein synthesis in eukaryotic cells by the guanine nucleotide exchange factor and chain initiation factor 2.\",\"authors\":\"L P Singh, A J Wahba\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>In eukaryotes, the guanine nucleotide exchange factor (eIF-2B) is a key protein in the control of polypeptide chain initiation. It catalyzes the exchange of chain initiation factor (eIF)-2-bound GDP for GTP and facilitates the formation of a ternary complex (eIF-2.GTP.Met-tRNAf). The activity of eIF-2B is inhibited indirectly by phosphorylation of the smallest subunit of eIF-2 which sequesters eIF-2B into an inactive eIF-2(alpha P).eIF-2B complex. On the other hand, eIF-2B activity may be regulated directly by covalent modification of its largest subunit with different kinases, such as casein kinase (CK)-I, CK-II and glycogen synthase kinase (GSK)-3. After stimulation of mammalian cells by insulin or growth factors, the allosteric activation of eIF-2B activity by sugar phosphates and inositol phosphates may also provide an important parameter in the regulation of protein synthesis.</p>\",\"PeriodicalId\":77373,\"journal\":{\"name\":\"SAAS bulletin, biochemistry and biotechnology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1996-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"SAAS bulletin, biochemistry and biotechnology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"SAAS bulletin, biochemistry and biotechnology","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
在真核生物中,鸟嘌呤核苷酸交换因子(eIF-2B)是控制多肽链起始的关键蛋白。它催化链起始因子(eIF)-2结合的GDP交换GTP,促进三元配合物(eIF-2.GTP. met - trnaf)的形成。eIF-2B的活性被eIF-2最小亚基的磷酸化间接抑制,该磷酸化将eIF-2B隔离成无活性的eIF-2(α P).eIF-2B复合物。另一方面,eIF-2B的活性可能通过其最大亚基与不同激酶(如酪蛋白激酶(CK)- 1、CK- ii和糖原合成酶激酶(GSK)-3)的共价修饰而直接调节。在哺乳动物细胞受到胰岛素或生长因子刺激后,磷酸糖和磷酸肌醇对eIF-2B活性的变构激活也可能为调节蛋白质合成提供重要参数。
Regulation of protein synthesis in eukaryotic cells by the guanine nucleotide exchange factor and chain initiation factor 2.
In eukaryotes, the guanine nucleotide exchange factor (eIF-2B) is a key protein in the control of polypeptide chain initiation. It catalyzes the exchange of chain initiation factor (eIF)-2-bound GDP for GTP and facilitates the formation of a ternary complex (eIF-2.GTP.Met-tRNAf). The activity of eIF-2B is inhibited indirectly by phosphorylation of the smallest subunit of eIF-2 which sequesters eIF-2B into an inactive eIF-2(alpha P).eIF-2B complex. On the other hand, eIF-2B activity may be regulated directly by covalent modification of its largest subunit with different kinases, such as casein kinase (CK)-I, CK-II and glycogen synthase kinase (GSK)-3. After stimulation of mammalian cells by insulin or growth factors, the allosteric activation of eIF-2B activity by sugar phosphates and inositol phosphates may also provide an important parameter in the regulation of protein synthesis.