An auxin-binding protein is localized to the plasma membrane of maize coleoptile cells: Identification by photoaffinity labeling and purification of a 23-kDa polypeptide

Journal Article · Wed Jan 15 04:00:00 EST 1992 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.89.2.475· OSTI ID:5617978

Feldwisch, J; Zettl, R; Hesse, F; Schell, J; Palme, K ^[1]

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1. Max-Planck-Inst. fuer Zuechtungsforschung, Koeln (West Germany)

Plasma membrane vesicles were isolated from maize (Zea mays L.) coleoptile tissue by aqueous two-phase partitioning and assayed for homogeneity by the use of membrane-specific enzymatic assays. Using 5-azido-(7-{sup 3}H)indole-3-acetic acid (({sup 3}H)N{sub 3}IAA), the authors identified several IAA-binding proteins with the molecular masses of 60 kDa (pm60), 58 kDa (pm58), and 23 kDa (pm23). Using Triton X-114, they were able to selectively extract pm23 from the plasma membrane. They show that auxins and functional analogues compete with ({sup 3}H)N{sub 3}IAA for binding to pm23. They found that PAB130, a polyclonal antibody raised against auxin-binding protein 1 (ABP-1), recognized ABP-1 as well as pm23. This suggests that pm23 shares common epitopes with ABP-1. In addition, they identified an auxin-binding protein with a molecular mass of 24 kDa (pm24), which was detected in microsomal but not in plasma membrane vesicle preparations. Like pm23 this protein was extracted from membrane vesicles with Triton X-114. They designed a purification scheme allowing simultaneous purification of pm23 and pm24. Homogeneous pm23 and pm24 were obtained from coleoptile extracts after 7,000-fold purification.

• OSTI ID: 5617978
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (United States) Vol. 89:2; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AROMATICS
AUXINS
AZAARENES
AZOLES
CELL CONSTITUENTS
CELL MEMBRANES
CEREALS
COLEOPTILE
GRAMINEAE
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
INDOLES
ISOTOPE APPLICATIONS
LILIOPSIDA
MAGNOLIOPHYTA
MAIZE
MEMBRANES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDES
PLANT GROWTH REGULATORS
PLANTS
POLYPEPTIDES
PROTEINS
PURIFICATION
PYRROLES
RADIORECEPTOR ASSAY
TRACER TECHNIQUES
TRITIUM COMPOUNDS