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Title: Isolation and characterization of cDNA clones for carrot extensin and a proline-rich 33-kDa protein

Journal Article · · Proc. Natl. Acad. Sci. U.S.A.; (United States)

Extensins are hydroxyproline-rich glycoproteins associated with most dicotyledonous plant cell walls. To isolate cDNA clones encoding extensin, the authors started by isolating poly(A) RNA from carrot root tissue, and then translating the RNA in vitro, in the presence of tritiated leucine or proline. A 33-kDa peptide was identified in the translation products as a putative extensin precursor. From a cDNA library constructed with poly(A) RNA from wounded carrots, one cDNA clone (pDC5) was identified that specifically hybridized to poly(A) RNA encoding this 33-kDa peptide. They isolated three cDNA clones (pDC11, pDC12, and pDC16) from another cDNA library using pCD5 as a probe. DNA sequence data, RNA hybridization analysis, and hybrid released in vitro translation indicate that the cDNA clones pDC11 encodes extensin and that cDNA clones pDC12 and pDC16 encode the 33-kDa peptide, which as yet has an unknown identity and function. The assumption that the 33-kDa peptide was an extensin precursor was invalid. RNA hybridization analysis showed that RNA encoded by both clone types is accumulated upon wounding.

Research Organization:
Washington Univ., St. Louis, MO
DOE Contract Number:
FG02-84ER13255
OSTI ID:
6290620
Journal Information:
Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 82:13
Country of Publication:
United States
Language:
English