Phosphorylation of the alpha-subunit of plant eukaryotic initiation factor 2 prevents its association with polysomes but does not considerably suppress protein synthesis

Zhigailov, Andrey V.; Stanbekova, Gulshan; Nizkorodova, Anna S.; Galiakparov, Nurbol; Gritsenko, Dilyara; Polimbetova, N. S.; Halford, Nigel G.; Iskakov, Bulat

doi:10.1016/j.plantsci.2022.111190

Cited by 2 publications

(1 citation statement)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Despite initial observations of a “PKR-like” activity in plants infected with viruses 13 – 16 , no specific kinase has been isolated, and the sequence of a potential PKR ortholog is notably absent from plant genomes 17 . Thus, GCN2 is the only recognizable plant eIF2α kinase targeting a similar serine residue in plant eIF2α 12 , 18 – 22 . In vitro studies have identified CK2 as a kinase targeting eIF2α and eIF2β subunits, although the in vivo significance of this phosphorylation remains uncertain 23 , 24 .…”

Section: Introductionmentioning

confidence: 99%

The phosphorylation of carboxyl-terminal eIF2α by SPA kinases contributes to enhanced translation efficiency during photomorphogenesis

Chang,

Huang,

Browning

et al. 2024

Nat Commun

View full text Add to dashboard Cite

Light triggers an enhancement of global translation during photomorphogenesis in Arabidopsis, but little is known about the underlying mechanisms. The phosphorylation of the α-subunit of eukaryotic initiation factor 2 (eIF2α) at a conserved serine residue in the N-terminus has been shown as an important mechanism for the regulation of protein synthesis in mammalian and yeast cells. However, whether the phosphorylation of this residue in plant eIF2α plays a role in regulation of translation remains elusive. Here, we show that the quadruple mutant of SUPPRESSOR OF PHYA-105 family members (SPA1-SPA4) display repressed translation efficiency after light illumination. Moreover, SPA1 directly phosphorylates the eIF2α C-terminus under light conditions. The C-term-phosphorylated eIF2α promotes translation efficiency and photomorphogenesis, whereas the C-term-unphosphorylated eIF2α results in a decreased translation efficiency. We also demonstrate that the phosphorylated eIF2α enhances ternary complex assembly by promoting its affinity to eIF2β and eIF2γ. This study reveals a unique mechanism by which light promotes translation via SPA1-mediated phosphorylation of the C-terminus of eIF2α in plants.

show abstract