Glycosyl‐phosphatidylinositol‐anchor addition signals are processed in Nicotiana tabacum

• Published in: The Plant journal : for cell and molecular biology Vol. 21; no. 1; pp. 43 - 52
• Main Authors: Takos, Adam M., Dry, Ian B., Soole, Kathleen L.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.01.2000; Blackwell Science
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Cell membranes. Ionic channels. Membrane pores; Cell physiology; Cell structures and functions; Cells, Cultured; DNA Primers; Fundamental and applied biological sciences. Psychology; Glycosylphosphatidylinositols - chemistry; Glycosylphosphatidylinositols - metabolism; Molecular and cellular biology; Molecular Sequence Data; Nicotiana - cytology; Nicotiana - metabolism; Plant physiology and development; Plants, Toxic; Plasma membrane and permeation; Protein Sorting Signals - chemistry; Protein Sorting Signals - metabolism; Recombinant Fusion Proteins - genetics; Leader peptide; Membrane protein; Stimulant plant; Nicotiana tabacum; C terminal-Sequence; Phosphatidylinositol; Ultrastructure; Dicotyledones; Angiospermae; Covalent bond; Spermatophyta; Solanaceae; Anchoring
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313x.2000.00651.x

Summary Recent studies have demonstrated the existence of glycosyl‐phosphatidylinositol (GPI)‐anchored proteins in higher plants. In this study we tested whether GPI‐addition signals from diverse evolutionary sources would function to link a GPI‐anchor to a reporter protein in plant cells. Tobacco protoplasts were transiently transfected with a truncated form of the Clostridium thermocellum endoglucanase E reporter gene (celE′) fused with a tobacco secretion signal (PR‐1a) at the N‐terminus and either a yeast (GAS1), mammalian (Thy‐1) or putative plant (LeAGP‐1) GPI‐anchor addition signal at the C‐terminus. The yeast and plant C‐terminal signals were found to be capable of directing the addition of a GPI‐anchor to the endoglucanase protein (EGE′) as shown by the sensitivity of the lipid component of GPI to phosphatidylinositol‐specific phospholipase C (PI‐PLC) digestion. In contrast, the mammalian signal was poorly processed for anchor addition. When EGE′ was fused to a truncated form of the LeAGP‐1 signal (missing three amino acids predicted to be critical to signal cleavage and anchor addition), a GPI‐anchor was not linked to the EGE′ protein indicating the necessity for the missing amino acids. Our results show the conservation of the properties of GPI‐signals in plant cells and that there may be some similar preferences in GPI‐addition signal sequences for yeast and plant cells.