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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
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
2016-11-30 16:59:14
@misc{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},
  keyword      = {Autophosphorylation,FF-ATPase,Inner membrane,Mitochondria,Potato (Solanum tuberosum L.) tubers,Protein phosphorylation},
  language     = {eng},
  number       = {12},
  pages        = {1271--1279},
  publisher    = {ARRAY(0x809e710)},
  series       = {Plant and Cell Physiology},
  title        = {Phosphoproteins and protein kinase activities intrinsic to inner membranes of potato tuber mitochondria},
  volume       = {40},
  year         = {1999},
}