Molecular cloning and further characterization of a probable plant vacuolar sorting receptor.

AUTOR(ES)

Paris, N

RESUMO

BP-80 is a type I integral membrane protein abundant in pea (Pisum sativum) clathrin-coated vesicles (CCVs) that binds with high affinity to vacuole-targeting determinants containing asparagine-proline-isoleucine-arginine. Here we present results from cDNA cloning and studies of its intracellular localization. Its sequence and sequences of homologs from Arabidopsis, rice (Oryza sativa), and maize (Zea mays) define a novel family of proteins unique to plants that is highly conserved in both monocotyledons and dicotyledons. The BP-80 protein is present in dilated ends of Golgi cisternae and in "prevacuoles," which are small vacuoles separate from but capable of fusing with lytic vacuoles. Its cytoplasmic tail contains a Tyr-X-X-hydrophobic residue motif associated with transmembrane proteins incorporated into CCVs. When transiently expressed in tobacco (Nicotiana tabacum) suspension-culture protoplasts, a truncated form lacking transmembrane and cytoplasmic domains was secreted. These results, coupled with previous studies of ligand-binding specificity and pH dependence, strongly support our hypothesis that BP-80 is a vacuolar sorting receptor that trafficks in CCVs between Golgi and a newly described prevacuolar compartment.

Documentos Relacionados

• Structural Requirements for Ligand Binding by a Probable Plant Vacuolar Sorting Receptor
• Purification and initial characterization of a potential plant vacuolar targeting receptor.
• Molecular cloning and characterization of the human A3 adenosine receptor.
• Molecular cloning and characterization of an adenosine receptor: the A3 adenosine receptor.
• Cloning and characterization of a fourth human somatostatin receptor.