Guanine nucleotide binding proteins in zucchini seedlings: Characterization and interactions with the NPA receptor

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Plant Physiology, Supplement; (USA)

OSTI ID:6650198

Lindeberg, M; Jacobs, M ^[1]

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1. Swarthmore College, PA (USA)

A microsomal membrane preparation from hypocotyls of dark-grown Cucurbita pepo L. seedlings contains specific high-affinity binding sites for the non-hydrolyzable GTP analog guanosine 5{prime}-({gamma}-thio) triphosphate (GTP-{gamma}-S). Both the binding affinity and the pattern of binding specificity for GTP and GTP analogs are similar to animal G-proteins, and two zucchini membrane proteins are recognized in western blots by antiserum specific for the {sigma} subunit of platelet G{sub s} protein. GTP-{gamma}-S can increase specific naphthylphthalamic acid (NPA) binding in zucchini microsomal membrane preparations, with its stimulation increasing with large tissue age. Al{sup +3} and F{sup {minus}} agents known to activate G-proteins - decreased NPA specific binding by ca. 15%. In tests of in vitro auxin transport employing zucchini plasma membrane vesicles, AlF{sup {minus}}{sub 4} strongly inhibited {sup 3}H-indoleacetic acid nor accumulation; GTP-{gamma}-S effects on this system will be discussed.

• OSTI ID: 6650198
• Journal Information: Plant Physiology, Supplement; (USA), Vol. 89:4; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HERBICIDES
RECEPTORS
MEMBRANE PROTEINS
CHEMICAL COMPOSITION
BIOCHEMICAL REACTION KINETICS
MICROSOMES
NUCLEOTIDES
SEEDLINGS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VEGETABLES
CELL CONSTITUENTS
FOOD
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
ORGANIC COMPOUNDS
ORGANOIDS
PESTICIDES
PLANTS
PROTEINS
REACTION KINETICS
RIBOSOMES
550201* - Biochemistry- Tracer Techniques