Henderson A B, Miller A H, Hardesty B
Proc Natl Acad Sci U S A. 1979 Jun;76(6):2605-9. doi: 10.1073/pnas.76.6.2605.
Three functionally related components that block peptide initiation have been identified in lysates of rabbit reticulocytes. The components function consecutively in a cascade type sequence of reactions to cause phosphorylation of eukaryotic peptide initiation factor 2 (eIF-2). The eIF-2 kinase activated as part of this sequence has been tentatively identified as the same protein kinase that is activated by heme deficiency as part of the hemin-controlled repressor (HCR) system. The first component in the sequence is heat stable and can be reversibly activated by heat or pressure. It activates a second, heat-labile, component that in turn directly or indirectly activates the hemin-controlled eIF-2 kinase. This heat-labile component appears to function through proteolysis. This reaction sequence is not detectably affected by heme or cyclic AMP and thus appears to provide an alternative mechanism, independent of heme, for activation of the cyclic AMP-independent eIF-2 kinase of the HCR system.
在兔网织红细胞裂解物中已鉴定出三种功能相关的可阻断肽起始的成分。这些成分在一系列级联反应中依次发挥作用，导致真核肽起始因子2（eIF-2）磷酸化。作为该序列一部分被激活的eIF-2激酶已初步鉴定为与作为血红素控制阻遏物（HCR）系统一部分被血红素缺乏激活的蛋白激酶相同。该序列中的第一个成分是热稳定的，可被热或压力可逆激活。它激活第二个热不稳定成分，该成分进而直接或间接激活血红素控制的eIF-2激酶。这种热不稳定成分似乎通过蛋白水解发挥作用。该反应序列未被血红素或环磷酸腺苷（cAMP）显著影响，因此似乎提供了一种独立于血红素的替代机制，用于激活HCR系统中不依赖环磷酸腺苷的eIF-2激酶。
