Gasparian M, Pusterla M, Baldan B, Downey PM, Rossetto O, de Laureto PP, Filippini F, Terzi M, Lo Schiavo F. Identification and characterization of an 18-kilodalton, VAMP-like protein in suspension-cultured carrot cells.
PLANT PHYSIOLOGY 2000;
122:25-34. [PMID:
10631246 PMCID:
PMC58841 DOI:
10.1104/pp.122.1.25]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/1999] [Accepted: 09/17/1999] [Indexed: 05/23/2023]
Abstract
Polyclonal antibodies raised against rat vesicle associated membrane protein-2 (VAMP-2) recognized, in carrot (Daucus carota) microsomes, two major polypeptides of 18 and 30 kD, respectively. A biochemical separation of intracellular membranes by a sucrose density gradient co-localized the two polypeptides as resident in light, dense microsomes, corresponding to the endoplasmic reticulum-enriched fractions. Purification of coated vesicles allowed us to distinguish the subcellular location of the 18-kD polypeptide from that of 30 kD. The 18-kD polypeptide is present in the non-clathrin-coated vesicle peak. Like other VAMPs, the carrot 18-kD polypeptide is proteolyzed by tetanus toxin after separation of coatomers. Amino acid sequence analysis of peptides obtained by digestion of the 18-kD carrot polypeptide with the endoproteinase Asp-N confirms it to be a member of the VAMP family, as is suggested by its molecular weight, vesicular localization, and toxin-induced cleavage.
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