Forisoma
Forisome (from Latin foris = "door wing" and Greek soma = "body") are protein complexes made from the sieve elements of butterflies . If the phloem is wounded , they experience a change in conformation which leads to the closure of the affected sieve tubes in the phloem.
Forisomes represent a class of P proteins specific to the Faboideae subfamily . They consist of several subunits, the so-called forisomettes , which in turn are composed of several proteins. In differentiated sieve elements, forisomes are present as an elongated complex approx. 30 µm in length. By increasing the cellular Ca 2+ concentration or the pH value , as occurs when the vascular bundles are damaged, a change in conformation occurs from the normally crystalline to a dispersed form, which completely closes the sieve plates within seconds and thus a loss of the in the phloem can prevent transported assimilates . The conformational change is reversible and does not require the cellular energy store adenosine triphosphate . Sudden changes in the osmotic value or the presence of detergents also trigger the change in conformation.
Web links
- Website of the Forisom Group at the University of Münster (English)
- Gundula Noll: Molecular biological characterization of the forisomes . (PDF; 2.7 MB) Inaugural dissertation at the University of Giessen, 2005.
- Determination of the force effect of chemo-mechanical protein aggregates (forisomes). (PDF; 566 kB) Fraunhofer Institute for Mechanics of Materials , 2007 (English)
Individual evidence
- ^ M Knoblauch, GA Noll, T Muller, D Prufer, I Schneider-Huther, D Scharner, AJE Van Bel, WS Peters: ATP-independent contractile proteins from plants . In: Nature Materials , 2, 2003, pp. 600-603, doi: 10.1038 / nmat960
- ↑ N Tuteja, P Umate, R Tuteja: Forisomes as calcium-protein complex energized: A historical perspective . In: Plant signaling & behavior , vol. 5, no.5 , 2010, PMID 20215879
- ↑ Michael Knoblauch, Winfried S. Peters, Katrin Ehlers, Aart JE van Bel: Reversible Calcium-Regulated Stopcocks in Legume Sieve Tubes . In: Plant Cell , Vol. 13, 2001, pp. 1221-1230