Plant Physiology 77:747-752 (1985)
© 1985 American Society of Plant Biologists
Articles
Biosynthesis and Intracellular Transport of 11S Globulin in Developing Pumpkin Cotyledons 1
Ikuko Hara-Nishimura2,
Mikio Nishimura and
Takashi Akazawa
Research Institute for Biochemical Regulation, School of Agriculture, Nagoya University, Chikusa, Nagoya 464, Japan
In vitro studies to explore the biosynthesis of 11S globulin developing cotyledons of pumpkin (Cucurbita sp.) demonstrated that 11S globulin is synthesized on membrane-bound polysomes. Mr of the translation products (preproglobulin) synthesized by the poly(A)+-RNA isolated from developing cotyledons were determined to be 64,000 and 59,000, which are larger than those of the mature globulin subunit (62,000 and 57,000). Preproglobulin is then cotranslationally processed by cleavage of the signal peptide to produce proglobulin. In vivo pulse-chase experiments showed the sequential transformation of the single-chain proglobulin to mature globulin subunit (disulfide-linked doublet polypeptides) indicating posttranslational modification of the proglobulin.
Subcellular fractionation of the pulse-chased intact cotyledons showed that the [35S]methionine label is detectable in proglobulin in rough endoplasmic reticulum shortly after the pulse label. With time, the labeled proteins move into other cellular fractions: proglobulin in the density = 1.24 grams per cubic centimeter fractions after 30 minutes and mature globulin subunit associated with protein bodies after 1 to 2 hours. The distribution of proglobulin in sucrose density gradients did not correspond with those of catalase (microbody marker) or fumarase (mitochondria marker). An accumulation of proglobulin occurred in the density = 1.24 grams per cubic centimeter fractions, whereas the mature globulin was scarcely detectable in this fraction. In contrast, proglobulin was not detected by immunochemical blotting analysis in the protein bodies prepared under the mild conditions from cotyledon protoplasts. The results suggest that the d = 1.24 grams per cubic centimeter fractions are engaged in the translocation of proglobulin into the protein bodies.
2 Recipient of a postdoctoral fellowship from the Japan Society for the Promotion of Science (JSPS), 1983.
1 This is paper no. 9 in a series "Pumpkin (Cucurbita sp.) Seed Globulin". Paper no. 8 is Ref. 11.
This article has been cited by other articles:
|
|
|
|
 
T. Shimada, E. Watanabe, K. Tamura, Y. Hayashi, M. Nishimura, and I. Hara-Nishimura
A Vacuolar Sorting Receptor PV72 on the Membrane of Vesicles that Accumulate Precursors of Seed Storage Proteins (PAC Vesicles)
Plant Cell Physiol.,
October 15, 2002;
43(10):
1086 - 1095.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. Watanabe, T. Shimada, M. Kuroyanagi, M. Nishimura, and I. Hara-Nishimura
Calcium-mediated Association of a Putative Vacuolar Sorting Receptor PV72 with a Propeptide of 2S Albumin
J. Biol. Chem.,
March 1, 2002;
277(10):
8708 - 8715.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. Mitsuhashi, Y. Hayashi, Y. Koumoto, T. Shimada, T. Fukasawa-Akada, M. Nishimura, and I. Hara-Nishimura
A Novel Membrane Protein That Is Transported to Protein Storage Vacuoles via Precursor-Accumulating Vesicles
PLANT CELL,
October 1, 2001;
13(10):
2361 - 2372.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. M. Herman and B. A. Larkins
Protein Storage Bodies and Vacuoles
PLANT CELL,
April 1, 1999;
11(4):
601 - 614.
[Full Text]
|
|
|
|
|
|
|
K. Yamada, T. Shimada, M. Kondo, M. Nishimura, and I. Hara-Nishimura
Multiple Functional Proteins Are Produced by Cleaving Asn-Gln Bonds of a Single Precursor by Vacuolar Processing Enzyme
J. Biol. Chem.,
January 22, 1999;
274(4):
2563 - 2570.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. Hara-Nishimura, T. Shimada, K. Hatano, Y. Takeuchi, and M. Nishimura
Transport of Storage Proteins to Protein Storage Vacuoles Is Mediated by Large Precursor-Accumulating Vesicles
PLANT CELL,
May 1, 1998;
10(5):
825 - 836.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
