TY - JOUR

T1 - A receptor for protein import into potato mitochondria

AU - Heins, Lisa

AU - Schmitz, Udo

PY - 1996/6

Y1 - 1996/6

N2 - Five potential surface receptors for protein import into plant mitochondria were identified by gentle trypsin treatment of intact mitochondria from potato tubers and subsequent preparation of outer mitochondrial membranes. One of them, a 23 kDa protein, was purified to homogeneity and analysed by direct protein sequencing. Copy DNA clones encoding the corresponding polypeptide were isolated with labelled oligonucleotides derived from the amino acid data. The 23 kDa protein shares significant sequence similarity with protein import receptors from fungal mitochondria and contains one of their typical tetratricopeptide motifs. Its integration into the outer membrane is independent of protease accessible surface receptors and not accompanied by proteolytic processing. Monospecific antibodies against the 23 kDa protein significantly reduce import capacity of isolated mitochondria indicating that this component is indeed involved in the recognition or import of precursor proteins. As in fungi, immunological inhibition of protein import with IgGs against a single receptor is incomplete suggesting the existence of other receptors in the outer mitochondrial membrane of plant mitochondria.

AB - Five potential surface receptors for protein import into plant mitochondria were identified by gentle trypsin treatment of intact mitochondria from potato tubers and subsequent preparation of outer mitochondrial membranes. One of them, a 23 kDa protein, was purified to homogeneity and analysed by direct protein sequencing. Copy DNA clones encoding the corresponding polypeptide were isolated with labelled oligonucleotides derived from the amino acid data. The 23 kDa protein shares significant sequence similarity with protein import receptors from fungal mitochondria and contains one of their typical tetratricopeptide motifs. Its integration into the outer membrane is independent of protease accessible surface receptors and not accompanied by proteolytic processing. Monospecific antibodies against the 23 kDa protein significantly reduce import capacity of isolated mitochondria indicating that this component is indeed involved in the recognition or import of precursor proteins. As in fungi, immunological inhibition of protein import with IgGs against a single receptor is incomplete suggesting the existence of other receptors in the outer mitochondrial membrane of plant mitochondria.

UR - http://www.scopus.com/inward/record.url?scp=0030160495&partnerID=8YFLogxK

U2 - 10.1046/j.1365-313X.1996.9060829.x

DO - 10.1046/j.1365-313X.1996.9060829.x

M3 - Article

C2 - 8696363

AN - SCOPUS:0030160495

VL - 9

SP - 829

EP - 839

JO - Plant Journal

JF - Plant Journal

SN - 0960-7412

IS - 6

ER -