Anti‐(p34 protein) antibodies inhibit ribosome binding to and protein translocation across the rough microsomal membrane

FEBS Letters

Ichimura, Tohru²  Omata, Saburo¹  Sugano, Hiroshi²  Uda, Yasuyo¹  Ohsumi, Tomoya²  Shindo, Yukiko¹ 

[1]Department of Biochemistry, Faculty of Science, Niigata University, 2-Igarashi, Niigata 950-21, Japan

[2]Department of Biosystem Science, Graduate School of Science and Technology 2-Igarashi, Niigata 950-21, Japan

关键词: Rough microsome;    Ribosome-binding protein;    Ribosome;    Protein translocation;    Rat;    Liver;    RM;    rough microsomes;    SDS;    sodium dodecyl sulfate;    PAGE;    polyacrylamide gel electrophoresis;    HEPES;    4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid;    EDTA;    ethylenediaminetetraacetic acid;    hPL;    human placental lactogen;    RSA;    rat serum albumin;   

DOI  :  10.1016/0014-5793(93)81799-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The p34 protein is a non-glycosylated, integral membrane protein characteristic of rough microsomes and is believed to play a role in the ribosome-membrane association. Here, antibodies directed against p34 were examined as to their inhibitory effect on ribosome binding to and protein translocation across the microsomal membrane. Preincubation of the stripped (ribosome-depleted) membrane with anti-p34 immunoglobulins (IgGs) or their Fab fragments led to more than 80% inhibition of the binding of ribosomes and their large (60S) subunit to the membrane. The inhibition was dependent on the amount of antibodies used, but comparable amounts of IgGs and Fab fragments from nonimmune serum had less effect. The p34 antibodies were also inhibitory for cotranslational translocation of secretory proteins, i.e. placental lactogen and serum albumin, across the membrane. These results suggest that p34 is involved in the binding of ribosomes to the microsomal membrane and that it is in close proximity to the protein translocation site in the microsomal membrane.

【 授权许可】

Unknown