GSBS Student Publications

Title

Aberrant membrane insertion of a cytoplasmic tail deletion mutant of the hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Biochemistry and Molecular Pharmacology; Department of Molecular Genetics and Microbiology

Date

2-1-1990

Document Type

Article

Medical Subject Headings

Amino Acid Sequence; Cell Membrane; Cell-Free System; *Chromosome Deletion; *DNA Transposable Elements; DNA, Viral; *Genes, Viral; HN Protein; Microsomes; Molecular Sequence Data; *Mutation; Newcastle disease virus; Plasmids; Polyribosomes; Protein Biosynthesis; Protein Sorting Signals; RNA, Messenger; Restriction Mapping; Sequence Homology, Nucleic Acid; Transcription, Genetic; Triticum; Viral Structural Proteins

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The hemagglutinin-neuraminidase (HN) protein of Newcastle disease virus (NDV) is a type II glycoprotein oriented in the plasma membrane with its amino terminus in the cytoplasm and its carboxy terminus external to the cell. We have previously shown that the membrane insertion of HN protein requires signal recognition particle SRP, occurs cotranslationally, and utilizes the same GTP-dependent step that has been described for secretory proteins, type I proteins, and multispanning proteins (C. Wilson, R. Gilmore, and T. Morrison, Mol. Cell. Biol. 7:1386-1392, 1987; C. Wilson, T. Connolly, T. Morrison, and R. Gilmore, J. Cell Biol. 107:69-77, 1988). The role of the amino-terminal cytoplasmic domain in the faithful membrane insertion of this type II protein was explored by characterizing the membrane integration of a mutant lacking 23 of the 26 amino acids of the cytoplasmic domain. The mutant protein was able to interact with SRP, resulting in translation inhibition, membrane targeting, and membrane translocation, but the efficiency of translocation was considerably lower than for the wild-type HN protein. In addition, a significant proportion of the mutant protein synthesized in the presence of SRP and microsomal membranes was associated with the membrane in an EDTA- and alkali-insensitive manner yet integrated into membranes with its carboxy-terminal domain on the cytoplasmic side of membrane vesicles. Membrane-integrated molecules with this reverse orientation were not detected when the mutant protein was synthesized in the absence of SRP or a functional SRP receptor. Truncated mRNAs encoding amino-terminal segments of the wild-type and mutant proteins were translated to prepare ribosomes bearing arrested nascent chains. The arrested mutant nascent chain, in contrast to the wild-type nascent chain, was also able to insert into membranes in a GTP- and SRP-independent manner. Results suggest that the cytoplasmic domain plays a role in the proper membrane insertion of this type II glycoprotein.

Rights and Permissions

Citation: Mol Cell Biol. 1990 Feb;10(2):449-57.

Related Resources

Link to Article in PubMed

Journal Title

Molecular and cellular biology

PubMed ID

2153915