Interaction of pollen-specific actin-depolymerizing factor with actin

• Published in: The Plant journal : for cell and molecular biology Vol. 25; no. 2; pp. 203 - 212
• Main Authors: SMERTENKO, Andrei P, ALLWOOD, Ellen G, KHAN, Safina, JIANG, Chang-Jie, MACIVER, Sutherland K, WEEDS, Alan G, HUSSEY, Patrick J
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Science 2001
• Subjects: Actin Depolymerizing Factors; Actins - metabolism; Agronomy. Soil science and plant productions; Biological and medical sciences; Destrin; Economic plant physiology; Flowering, floral biology, reproduction patterns; Fundamental and applied biological sciences. Psychology; Growth and development; Magnoliopsida - metabolism; Microfilament Proteins - metabolism; Plant physiology and development; Pollen - metabolism; Recombinant Proteins - metabolism; Sexual reproduction; Vegetative and sexual reproduction, floral biology, fructification; Monocotyledones; Organization; Zea mays; Germination; Interaction; Polymerization; Fecundation; Pollen tube; Depolymerization; Gramineae; Actin; Angiospermae; Cytoskeleton; Spermatophyta; Pollen
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.2001.00954.x

We have examined the interaction of recombinant lily pollen ADF, LlADF1, with actin and found that whilst it bound both G- and F-actin, it had a much smaller effect on the polymerization and depolymerization rate constants than the maize vegetative ADF, ZmADF3. An antiserum specific to pollen ADF, antipADF, was raised and used to localize pollen ADF in daffodil--a plant in which massive reorganizations of the actin cytoskeleton have been seen to occur as pollen enters and exits dormancy. We show, for the first time, an ADF decorating F-actin in cells that did not result from artificial increase in ADF concentration. In dehydrated pollen this ADF : actin array is replaced by actin : ADF rodlets and aggregates of actin, which presumably act as a storage form of actin during dormancy. In germinated pollen ADF has no specific localization, except when an adhesion is made at the tip where actin and ADF now co-localize. These activities of pollen ADF are discussed with reference to the activities of ZmADF3 and other members of the ADF/cofilin group of proteins.