Post-Golgi vesicles cotransport docosahexaenoyl-phospholipids and rhodopsin during frog photoreceptor membrane biogenesis. 1997

E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
LSU Neuroscience Center and Department of Ophthalmology, Louisiana State University Medical Center, School of Medicine, New Orleans, Louisiana 70112, USA.

Post-Golgi vesicles budding from the trans-Golgi network (TGN) are involved in the vectorial transport and delivery of rhodopsin to photoreceptor rod outer segments (ROS). We report here that newly synthesized docosahexaenoyl (DHA) phospholipids are sequestered and cotransported by rhodopsin-bearing post-Golgi vesicles to ROS. Frog retinas were pulse-labeled with [35S]methionine/cysteine and [3H]DHA prior to ROS isolation and subcellular fractionation. After a 1-h pulse, relatively uniform [3H]DHA-lipid labeling (DPM/microg protein) was observed in all fractions enriched in post-Golgi vesicles, TGN, Golgi, and endoplasmic reticulum (ER) membranes. During the subsequent 2-h chase translocation of free [3H]DHA from ROS to the photoreceptor inner segment contributed to an additional overall increase in labeling of lipids. The specific activity (dpm/nmol DHA) in ER-enriched fraction was similar or higher than in other subcellular fractions after both the pulse and the chase, indicating that the bulk of [3H]DHA-lipids was synthesized in the ER. After the chase a 2-fold increase in labeling of lipids in the ER and Golgi and a 2.6-fold in lighter TGN-enriched fractions was observed. The highest labeling was in the post-Golgi vesicle fraction (4-fold increase), with [3H]DHA-phosphatidylcholine and [3H]DHA-phosphatidylethanolamine showing the greatest increase. At the same time, newly synthesized [35S]rhodopsin shifted from the ER and Golgi toward TGN and post-Golgi fractions. Therefore, sequestration and association of [35S]rhodopsin and [3H]DHA-lipids in a TGN membrane domain occurs prior to their exit and subsequent vectorial cotransport on post-Golgi vesicles to ROS. Labeling of ROS lipids was very low, with phosphatidylinositol and diacylglycerols displaying the highest labeling. This indicates that other mechanisms by-passing Golgi, i.e. facilitated by lipid carrier proteins, may also contribute to molecular replacement of disc membrane DHA-phospholipids, particularly phosphatidylinositol.

UI MeSH Term Description Entries
D008715 Methionine A sulfur-containing essential L-amino acid that is important in many body functions. L-Methionine,Liquimeth,Methionine, L-Isomer,Pedameth,L-Isomer Methionine,Methionine, L Isomer
D010743 Phospholipids Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system. Phosphatides,Phospholipid
D010786 Photoreceptor Cells Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade. Ciliary Photoreceptor Cells,Ciliary Photoreceptors,Rhabdomeric Photoreceptor Cells,Rhabdomeric Photoreceptors,Cell, Ciliary Photoreceptor,Cell, Photoreceptor,Cell, Rhabdomeric Photoreceptor,Cells, Ciliary Photoreceptor,Cells, Photoreceptor,Cells, Rhabdomeric Photoreceptor,Ciliary Photoreceptor,Ciliary Photoreceptor Cell,Photoreceptor Cell,Photoreceptor Cell, Ciliary,Photoreceptor Cell, Rhabdomeric,Photoreceptor Cells, Ciliary,Photoreceptor Cells, Rhabdomeric,Photoreceptor, Ciliary,Photoreceptor, Rhabdomeric,Photoreceptors, Ciliary,Photoreceptors, Rhabdomeric,Rhabdomeric Photoreceptor,Rhabdomeric Photoreceptor Cell
D011898 Ranidae The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica. Frogs, True,Rana,Frog, True,True Frog,True Frogs
D012160 Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent. Ora Serrata
D003545 Cysteine A thiol-containing non-essential amino acid that is oxidized to form CYSTINE. Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine
D004281 Docosahexaenoic Acids C22-unsaturated fatty acids found predominantly in FISH OILS. Docosahexaenoate,Docosahexaenoic Acid,Docosahexenoic Acids,Docosahexaenoic Acid (All-Z Isomer),Docosahexaenoic Acid Dimer (All-Z Isomer),Docosahexaenoic Acid, 3,6,9,12,15,18-Isomer,Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer),Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer), Cerium Salt,Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer), Cesium Salt,Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer), Potassium Salt,Docosahexaenoic Acid, 4,7,10,13,16,19-(Z,Z,Z,Z,Z,E-Isomer),Docosahexaenoic Acid, 4,7,10,13,16,19-Isomer,Docosahexaenoic Acid, 4,7,10,13,16,19-Isomer, Sodium Salt,Docosahexaenoic Acid, Sodium Salt,Acid, Docosahexaenoic,Acids, Docosahexaenoic,Acids, Docosahexenoic
D005230 Fatty Acids, Nonesterified FATTY ACIDS found in the plasma that are complexed with SERUM ALBUMIN for transport. These fatty acids are not in glycerol ester form. Fatty Acids, Free,Free Fatty Acid,Free Fatty Acids,NEFA,Acid, Free Fatty,Acids, Free Fatty,Acids, Nonesterified Fatty,Fatty Acid, Free,Nonesterified Fatty Acids
D006056 Golgi Apparatus A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990) Golgi Complex,Apparatus, Golgi,Complex, Golgi
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

Related Publications

E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
June 1991, The Journal of cell biology,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
January 1978, Uspekhi sovremennoi biologii,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
December 1997, Electrophoresis,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
January 1971, Biofizika,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
February 1970, Nature,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
October 2000, Electrophoresis,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
November 1977, Biokhimiia (Moscow, Russia),
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
April 1979, The Journal of membrane biology,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
June 2009, Molecular microbiology,
E B Rodriguez de Turco, and D Deretic, and N G Bazan, and D S Papermaster
February 1974, Nature,
Copied contents to your clipboard!