Specific photoaffinity labeling of two plasma membrane polypeptides with an azido auxin

Journal Article · Sat Jul 01 04:00:00 EDT 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.13.4948· OSTI ID:5264213

Hicks, G R; Rayle, D L; Jones, A M; Lomax, T L ^[1]

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1. Oregon State Univ., Corvallis (USA)

Plasma membrane vesicles were isolated from zucchini (Cucurbita pepo) hypocotyl tissue by aqueous phase partitioning and assessed for homogeneity by the use of membrane-specific enzyme assays. The highly pure plasma membrane vesicles maintained a pH differential across the membrane and accumulated a tritiated azido analogue of 3-indoleacetic acid (IAA), 5-azido-(7-{sup 3}H)IAA(({sup 3}H)N{sub 3}IAA), in a manner similar to the accumulation of ({sup 3}H)IAA. The association of the ({sup 3}H)N{sub 3}IAA with membrane vesicles was saturable and subject to competition by IAA and auxin analogues. Auxin-binding proteins were photoaffinity labeled by addition of ({sup 3}H)N{sub 3}IAA to plasma membrane vesicles prior to exposure to UV light and detected by subsequent NaDodSO{sub 4}/PAGE and fluorography. When the reaction temperature was lowered to {minus}196{degree}C, high-specific-activity labeling of a 40-kDa and a 42-kDa polypeptide was observed. Collectively, these results suggest that the radiolabeled polypeptides are auxin receptors. The covalent nature of the label should facilitate purification and further characterization of the receptors.

• OSTI ID: 5264213
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 86:13; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AUXINS
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL MEMBRANES
ELECTROMAGNETIC RADIATION
ELECTROPHORESIS
FAR ULTRAVIOLET RADIATION
HYDROGEN COMPOUNDS
KINETICS
MEMBRANE PROTEINS
MEMBRANES
MOLECULAR STRUCTURE
ORGANIC COMPOUNDS
PEPTIDES
PLANT GROWTH REGULATORS
POLYPEPTIDES
PROTEINS
RADIATIONS
REACTION KINETICS
RECEPTORS
SEEDS
TRITIUM COMPOUNDS
ULTRAVIOLET RADIATION