title: Signal recognition-like particles are present in maize.
abstract: We show that maize storage protein translocation across microsomal membranes is mediated by signal recognition particles (SRPs) similar to those described in animal systems (Dobberstein, B. (1978) Hoppe-Seyler's Z. Physiol. Chem. 252, 955-962; Walter, P., and Blobel, G. (1980) Proc. Natl. Acad. Sci. U. S. A. 77, 7112-7116). We have prepared a high salt extract from endosperm cell homogenates, from which a ribosome-free fraction was obtained. This fraction is enriched in an SRP-like factor which apparently corresponds to a ribonucleoprotein particle that sediments at about 12 S. The RNA moiety of this 12 S particle is complex, showing a three-band electrophoretic pattern and sedimenting at about 8 S. The fraction restores translocation competence of salt-washed maize microsomes as tested by using a pre-zein message. In contrast to canine SRPs, the maize SRP-like component does not cause a translation arrest of maize storage proteins (zein) in a wheat germ cell-free system.
authors: Departamento de Biologia Molecular i Agrobiologia, Centre d'Investigació i Desenvolupament Consejo Superior de Investigacions Cientificas, Jordi Girona Salgado, Barcelona, Spain.
authors: N
authors: N
authors: Campos
authors: J
authors: J
authors: Palau
authors: M
authors: M
authors: Torrent
authors: D
authors: D
authors: Ludevid
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D008836:Micrococcal Nuclease / Q000494:pharmacology; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D010179:Pancreas / Q000648:ultrastructure; D010944:Plants / Q000032:analysis*; D014176:Protein Biosynthesis; D012313:RNA / Q000032:analysis; D012261:Ribonucleoproteins / Q000032:analysis* / Q000494:pharmacology; D018271:Signal Recognition Particle; D014158:Transcription, Genetic; D003313:Zea mays; D015028:Zein / Q000235:genetics / Q000378:metabolism
chemical_list: D012261:Ribonucleoproteins; D018271:Signal Recognition Particle; D012313:RNA; D015028:Zein; D008836:Micrococcal Nuclease