Interaction of a potential vacuolar targeting receptor with amino- and carboxyl-terminal targeting determinants.
A protein of 80 kD from developing pea (Pisum sativum) cotyledons has previously been shown to exhibit characteristics of a vacuolar targeting receptor by means of its affinity for the amino-terminal vacuolar targeting sequence of proaleurain from barley (Hordeum vulgare). In this report we show that the same protein also binds to the amino-terminal targeting peptide of prosporamin from sweet potato (Ipomoea batatas) and to the carboxyl-terminal targeting determinant of pro-2S albumin from Brazil nut (Bertholletia excelsa). The receptor protein does not bind to the carboxyl-terminal propeptide (representing the targeting sequence) of barley lectin. The binding of the 80-kD protein to the sporamin determinant involves a motif (NPIR) that has been shown to be crucial for vacuolar targeting in vivo. The binding to the carboxyl-terminal targeting determinant of pro-2S albumin appears to involve the carboxyl-terminal propeptide and the adjacent five amino acids of the mature protein. The 80-kD protein does not bind to peptide sequences that have been shown to be incompetent in directing vacuolar targeting.
Kirsch
T
T
Department of Botany and Microbiology, University of Oklahoma, Norman, 73019, USA.
Saalbach
G
G
Raikhel
N V
NV
Beevers
L
L
D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010944:Plants / Q000235:genetics / Q000378:metabolism; D011228:Prealbumin / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*
D010940:Plant Proteins; D011228:Prealbumin; D018160:Receptors, Cytoplasmic and Nuclear; C067142:sporamin protein, Ipomoea batatas