The plastoglobule-localized protein AtABC1K6 is a Mn²⁺-dependent kinase necessary for timely transition to reproductive growth.

ABSTRACT: The Absence of bc₁ Complex (ABC1) is an ancient, atypical protein kinase family that emerged prior to the archaeal-eubacterial divergence. Loss-of-function mutants in ABC1 genes are linked to respiratory defects in microbes and humans and to compromised photosynthetic performance and stress tolerance in plants. However, demonstration of protein kinase activity remains elusive, hampering their study. Here, we investigate a homolog from Arabidopsis thaliana, AtABC1K6, and demonstrate in vitro autophosphorylation activity, which we replicate with a human ABC1 ortholog. We also show that AtABC1K6 protein kinase activity requires an atypical buffer composition, including Mn²⁺ as a divalent cation cofactor and a low salt concentration. AtABC1K6 associates with plastoglobule

SUBMITTER: Espinoza-Corral R 

PROVIDER: S-EPMC8956952 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature