Chloroplast protein synthesis: thylakoid bound polysomes synthesize thylakoid proteins

Conference · Tue Apr 01 00:00:00 EST 1986 · Plant Physiol.; (United States)

OSTI ID:5495343

Hurewitz, J; Jagendorf, A T

Previous work indicated more polysomes bound to pea thylakoids in light than in the dark, in vivo. With isolated intact chloroplasts incubated in darkness, 24 to 74% more RNA was thylakoid-bound at pH 8.3 than at pH 7. Thus the major effect of light in vivo may be due to higher stroma pH. In isolated pea chloroplasts, initiation inhibitors (pactamycin and kanamycin) decreased the extent of RNA binding, and elongation inhibitors (lincomycin and streptomycin) increased it. Thus translation initiation and termination probably control the cycling of bound ribosomes. While only 3 to 6% of total RNA is in bound polysomes the incorporation of /sup 3/H-Leu into thylakoids was proportional to the amount of this bound RNA. When Micrococcal nuclease-treated thylakoids were added to labeled runoff translation products of stroma ribosomes, less than 1% of the label adhered to the added membranes; but 37% of the labeled products made by thylakoid polysomes were bound. These data support the concept that stroma ribosomes are recruited into thylakoid proteins.

• Research Organization: Cornell Univ., Ithaca, NY
• OSTI ID: 5495343
• Journal Information: Plant Physiol.; (United States), Vol. 80:4; Conference: Annual meeting of the American Society of Plant Physiologists, Baton Rouge, LA, USA, 8-12 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PROTEINS
BIOSYNTHESIS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL PATHWAYS
CHLOROPLASTS
LEUCINE
PH VALUE
PHOTOSYNTHETIC MEMBRANES
PISUM
RNA
TRITIUM COMPOUNDS
AMINO ACIDS
BACTERIA
CARBOXYLIC ACIDS
CELL CONSTITUENTS
KINETICS
LABELLED COMPOUNDS
LEGUMINOSAE
MEMBRANES
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PLANTS
REACTION KINETICS
RHIZOBIUM
SYNTHESIS
551001* - Physiological Systems- Tracer Techniques