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United States Department of Agriculture

Agricultural Research Service

Title: STIL, a peculiar molecule from styles, specifically dephosphorylates the pollen receptor kinase LePRK2 and stimulates pollen tube growth in vitro)

Author
item Wengier, Diego l.
item Mazzeklla, Maria a.
item Salem, Tamara m.
item Mccormick, Sheila
item Muschietti, Jorge p.

Submitted to: Biomed Central (BMC) Plant Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/22/2010
Publication Date: 2/22/2010
Publication URL: www.biomedcentral.com/content/pdf/1471-2229-10-33.pdf
Citation: Wengier, D., Mazzeklla, M., Salem, T., Mccormick, S.M., Muschietti, J. 2010. STIL, a peculiar molecule from styles, specifically dephosphorylates the pollen receptor kinase LePRK2 and stimulates pollen tube growth in vitro. Biomed Central (BMC) Plant Biology. Online 1471-2229/10/33.

Interpretive Summary: LePRK2 is a pollen receptor kinase that is dephosphorylated when incubated with style extracts. Here we show that LePRK2 dephosphorylation is mediated by a highly resistant molecule from styles, that we named STIL (for Style Interactor for LePRKs). STIL increased pollen tube lengths of in vitro germinated pollen.

Technical Abstract: BACKGROUND: LePRK1 and LePRK2 are two pollen receptor kinases localized to the plasma membrane, where they are present in a high molecular weight complex (LePRK complex). LePRK2 is phosphorylated in mature and germinated pollen, but is dephosphorylated when pollen membranes are incubated with tomato or tobacco style extracts. RESULTS: Here we show that LePRK2 dephosphorylation is mediated by a heat-, acid-, base-, DTT- and proteaseresistant component from tobacco styles. Using LePRK2 phosphorylation as a tracking assay for purification, style exudates were subjected to chloroform extraction, anionic exchange, and C18 reverse-phase chromatography columns. We finally obtained a single ~3,550 Da compound (as determined by UV-MALDI-TOF MS) that we named STIL (for Style Interactor for LePRKs). STIL increased pollen tube lengths of in vitro germinated pollen in a dosedependent manner. CONCLUSION: We propose that the LePRK complex perceives STIL, resulting in LePRK2 dephosphorylation and an increase in pollen tube growth.

Last Modified: 8/24/2016
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