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Phosphoproteins and protein kinase activities intrinsic to inner membranes of potato tuber mitochondria

Struglics, André LU ; Fredlund, Kenneth M. ; Møller, Ian M. and Allen, John F. LU (1999) In Plant and Cell Physiology 40(12). p.1271-1279
Abstract

Inside-out submitochondrial particles (IO-SMP) were isolated and purified from potato (Solanum tuberosum L. cv.) tubers. When these IO-SMP were incubated with [γ32P]ATP more then 20 proteins became labelled as a result of phosphorylation. The 32P incorporation was stimulated by the oxidizing reagent ferricyanide. Except for a 17 kDa protein which was phosphorylated only in the absence of divalent cations, the protein phosphorylation required Mg2+. The time for half-maximum 32P incorporation was 4 min for the 22 kDa phospho-F1 δ-subunit and 2 min for the 28 kDa phospho-F0 b-subunit of the proton-ATPase. The K(m) for ATP for the detected phosphoproteins was between 65 μM... (More)

Inside-out submitochondrial particles (IO-SMP) were isolated and purified from potato (Solanum tuberosum L. cv.) tubers. When these IO-SMP were incubated with [γ32P]ATP more then 20 proteins became labelled as a result of phosphorylation. The 32P incorporation was stimulated by the oxidizing reagent ferricyanide. Except for a 17 kDa protein which was phosphorylated only in the absence of divalent cations, the protein phosphorylation required Mg2+. The time for half-maximum 32P incorporation was 4 min for the 22 kDa phospho-F1 δ-subunit and 2 min for the 28 kDa phospho-F0 b-subunit of the proton-ATPase. The K(m) for ATP for the detected phosphoproteins was between 65 μM and 110 μM. The pH optimum for protein phosphorylation in inner membranes was between pH 6 and 8, and for the F1 δ-subunit and the F0 b-subunit the pH optima were 6.5-8 and pH 8, respectively. A 37 kDa phosphoprotein was phosphorylated on a histidine residue while the remainder of the inner membrane proteins were phosphorylated on serine or threonine residues. Two autophosphorylated putative kinases were identified: one at 16.5 kDa required divalent cations for autophosphorylation, while another at 30 kDa did not. A 110 kDa protein was labelled only with [α-32P]ATP, suggesting adenylylation.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
keywords
Autophosphorylation, FF-ATPase, Inner membrane, Mitochondria, Potato (Solanum tuberosum L.) tubers, Protein phosphorylation
in
Plant and Cell Physiology
volume
40
issue
12
pages
9 pages
publisher
Oxford University Press
external identifiers
  • scopus:0033397455
ISSN
0032-0781
language
English
LU publication?
yes
id
62f3985e-a946-40ca-a489-6a8f8076cf24
date added to LUP
2016-10-14 16:00:08
date last changed
2022-01-30 06:51:00
@article{62f3985e-a946-40ca-a489-6a8f8076cf24,
  abstract     = {{<p>Inside-out submitochondrial particles (IO-SMP) were isolated and purified from potato (Solanum tuberosum L. cv.) tubers. When these IO-SMP were incubated with [γ<sup>32</sup>P]ATP more then 20 proteins became labelled as a result of phosphorylation. The <sup>32</sup>P incorporation was stimulated by the oxidizing reagent ferricyanide. Except for a 17 kDa protein which was phosphorylated only in the absence of divalent cations, the protein phosphorylation required Mg<sup>2+</sup>. The time for half-maximum <sup>32</sup>P incorporation was 4 min for the 22 kDa phospho-F<sub>1</sub> δ-subunit and 2 min for the 28 kDa phospho-F<sub>0</sub> b-subunit of the proton-ATPase. The K(m) for ATP for the detected phosphoproteins was between 65 μM and 110 μM. The pH optimum for protein phosphorylation in inner membranes was between pH 6 and 8, and for the F<sub>1</sub> δ-subunit and the F<sub>0</sub> b-subunit the pH optima were 6.5-8 and pH 8, respectively. A 37 kDa phosphoprotein was phosphorylated on a histidine residue while the remainder of the inner membrane proteins were phosphorylated on serine or threonine residues. Two autophosphorylated putative kinases were identified: one at 16.5 kDa required divalent cations for autophosphorylation, while another at 30 kDa did not. A 110 kDa protein was labelled only with [α-<sup>32</sup>P]ATP, suggesting adenylylation.</p>}},
  author       = {{Struglics, André and Fredlund, Kenneth M. and Møller, Ian M. and Allen, John F.}},
  issn         = {{0032-0781}},
  keywords     = {{Autophosphorylation; FF-ATPase; Inner membrane; Mitochondria; Potato (Solanum tuberosum L.) tubers; Protein phosphorylation}},
  language     = {{eng}},
  number       = {{12}},
  pages        = {{1271--1279}},
  publisher    = {{Oxford University Press}},
  series       = {{Plant and Cell Physiology}},
  title        = {{Phosphoproteins and protein kinase activities intrinsic to inner membranes of potato tuber mitochondria}},
  volume       = {{40}},
  year         = {{1999}},
}