Antisense inhibition of plastidial phosphoglucomutase provides compelling evidence that potato tuber amyloplasts import carbon from the cytosol in the form of glucose-6-phosphate.

The aim of this work was to establish whether plastidial phosphoglucomutase is involved in the starch biosynthetic pathway of potato tubers and thereby to determine the form in which carbon is imported into the potato amyloplast. For this purpose, we cloned the plastidial isoform of potato PGM (StpPGM), and using an antisense approach generated transgenic potato plants that exhibited decreased expression of the StpPGM gene and contained significantly reduced total phosphoglucomutase activity. We confirmed that this loss in activity was due specifically to a reduction in plastidial PGM activity.

The general mitochondrial processing peptidase from wheat is integrated into the cytochrome bc1-complex of the respiratory chain.

The bc1-complex (EC 1.10.2.

The mitochondrial processing peptidase from potato: a self-processing enzyme encoded by two differentially expressed genes.

Cytochrome c reductase from potato is a bifunctional protein complex located in the inner mitochondrial membrane, which is involved in respiratory electron transport and processing of mitochondrial precursor proteins. The three largest subunits of the complex share the highest degree of sequence identity with the alpha- and beta-subunits of the soluble processing peptidase (MPP) from fungi and mammals. Evidence is provided that another substoichiometric polypeptide of the cytochrome c reductase complex resembles the alpha-subunit of MPP.

Primary structure and expression of a gene encoding the cytosolic ribosomal protein S4 from potato.

The primary structure of a cDNA clone encoding the S4 protein from the small subunit of 80S ribosomes from potato was determined. Cytosolic ribosomal protein S4 is hydrophilic and has a prevalence for positively charged residues. In potato it is 264 amino acids long and contains a putative nuclear targeting signal close to the N-terminus.