Large alkyl side-chains of isoleucine and leucine in the NPIRL region constitute the core of the vacuolar sorting determinant of sporamin precursor

Ken Matsuoka, Kenzo Nakamura

Research output: Contribution to journalArticle

45 Citations (Scopus)


The N-terminal propeptide of the sporamin precursor contains vacuolar targeting information within the Asn-26/Pro-27/Ile-28/Arg-29/Leu-30 (NPIRL) sequence. An Agrobacterium-mediated transient expression assay with tobacco BY-2 cells was employed to investigate the role of each amino acid of the NPIRL region in vacuolar targeting. Replacement of Asn-26, Pro-27, Ile-28 and Leu-30 with several amino acids caused secretion of the mutant prosporamin. Leu was the only amino acid that could be substituted for Ile-28 without affecting transport. Exchange of Leu-30 for amino acids with small side-chains abolished vacuolar delivery. These results indicate that the consensus composition of the NPIRL sequence is [preferably Asn]-[not acidic]-[Ile or Leu]-[any amino acid]-[large and hydrophobic] and suggest that the large alkyl side-chains of Ile-28 and Leu-30 constitute the core of the vacuolar sorting determinant.

Original languageEnglish
Pages (from-to)825-835
Number of pages11
JournalPlant Molecular Biology
Issue number6
Publication statusPublished - Dec 1 1999
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Agronomy and Crop Science
  • Genetics
  • Plant Science

Cite this