Unexpected localization of a lipid transfer protein in germinating sunflower seeds.
Plant lipid transfer proteins (LTPs) are low-molecular-mass proteins whose biological function still remains elusive. They are synthesized with a signal peptide that drives them to the secretory pathway. We have previously described the occurrence of an apoplastic LTP named Ha-AP10, present in sunflower seeds. Using a biochemical approach we now demonstrate that a fraction of Ha-AP10 is perispherically bound to membranes of germinating seeds. Purification of plasma membranes revealed the presence of Ha-AP10 in this fraction. Fluorimmunolocalization studies on germinating sunflower seeds demonstrated that in addition to the apoplastic and plasma membrane localization, Ha-AP10 is also present intracellularlly associated to unidentified structures. This varied distribution of Ha-AP10 in sunflower seeds may give novel clues to understand the role of LTPs in seed physiology.
Pagnussat
Luciana A
LA
Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata-CONICET, Funes 3250, 7600-Mar del Plata, Argentina.
Lombardo
Cristina
C
Regente
Mariana
M
Pinedo
Marcela
M
Martín
Mariana
M
de la Canal
Laura
L
D052179:Antigens, Plant / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D018525:Germination; D006368:Helianthus / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D042541:Intracellular Space / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D021381:Protein Transport; D012639:Seeds / Q000254:growth & development / Q000378:metabolism*; D012995:Solubility
D052179:Antigens, Plant; D002352:Carrier Proteins; D010940:Plant Proteins; C511920:lipid transfer proteins, plant