scholarly journals Truncations of the C-terminal cytoplasmic domain of MG160, a medial Golgi sialoglycoprotein, result in its partial transport to the plasma membrane and filopodia

1998 ◽  
Vol 111 (2) ◽  
pp. 249-260 ◽  
Author(s):  
J.O. Gonatas ◽  
Y.J. Chen ◽  
A. Stieber ◽  
Z. Mourelatos ◽  
N.K. Gonatas
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Cell Surface ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Growth Factor Receptor ◽  
Cytoplasmic Domain ◽  
Type I ◽  
Ovary Cells

MG160, a type I cysteine-rich membrane sialoglycoprotein residing in the medial cisternae of the rat Golgi apparatus, is highly homologous to CFR, a fibroblast growth factor receptor, and ESL-1, an E-selectin ligand located at the cell surface of mouse myeloid cells and recently detected in the Golgi apparatus as well. The mechanism for the transport of MG160 from the Golgi apparatus to the cell surface is unknown. In this study we found that differential processing of the carboxy-terminal cytoplasmic domain (CD), consisting of amino acids Arg1159 Ile Thr Lys Arg Val Thr Arg Glu Leu Lys Asp Arg1171, resulted in the partial transport of the protein to the plasma membrane and filopodia. In Chinese hamster ovary cells (CHO), stably transfected with the entire cDNA encoding MG160, the protein was localized in the Golgi apparatus. However, when the terminal Arg1171 or up to nine distal amino acids were deleted, the protein was distributed to the plasma membrane and filopodia as well as the Golgi apparatus. This report shows that the CD of an endogenous type I Golgi protein is important for its efficient retention and identifies a unique residue preference in this process. Cleavage within the CD of MG160 may constitute a regulatory mechanism for the partial export of the protein from the Golgi apparatus to the plasma membrane and filopodia.

scholarly journals The amino terminus of GLUT4 functions as an internalization motif but not an intracellular retention signal when substituted for the transferrin receptor cytoplasmic domain

1994 ◽  
Vol 124 (5) ◽  
pp. 705-715 ◽  
Author(s):  
RJ Garippa ◽  
TW Judge ◽  
DE James ◽  
TE McGraw
Keyword(s):  
Cell Surface ◽  
Transferrin Receptor ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Cytoplasmic Domain ◽  
Amino Terminus ◽  
Ovary Cells ◽  
Major Function ◽  
Amino Terminal ◽  
Human Transferrin Receptor

Previous studies have demonstrated that the amino-terminal cytoplasmic domain of GLUT4 contains a phenylalanine-based targeting motif that determines its steady state distribution between the surface and the interior of cells (Piper, R. C., C. Tai, P. Kuleza, S. Pang, D. Warnock, J. Baenziger, J. W. Slot, H. J. Geuze, C. Puri, and D. E. James. 1993. J. Cell Biol. 121:1221). To directly measure the effect that the GLUT4 amino terminus has on internalization and subsequent recycling back to the cell surface, we constructed chimeras in which this sequence was substituted for the amino-terminal cytoplasmic domain of the human transferrin receptor. The chimeras were stably transfected into Chinese hamster ovary cells and their endocytic behavior characterized. The GLUT4-transferrin receptor chimera was recycled back to the cell surface with a rate similar to the transferrin receptor, indicating that the GLUT4 sequence was not promoting intracellular retention of the chimera. The GLUT4-transferrin receptor chimera was internalized at half the rate of the transferrin receptor. Substitution of an alanine for phenylalanine at position 5 slowed internalization of the chimera by twofold, to a level characteristic of bulk membrane internalization. However, substitution of a tyrosine increased the rate of internalization to the level of the transferrin receptor. Neither of these substitutions significantly altered the rate at which the chimeras were recycled back to the cell surface. These results demonstrate that the major function of the GLUT4 amino-terminal domain is to promote the effective internalization of the protein from the cell surface, via a functional phenylalanine-based internalization motif, rather than retention of the transporter within intracellular structures.

Metabolism of peptide amino acids by Chinese hamster ovary cells grown in a complex medium

1999 ◽  
Vol 62 (3) ◽  
pp. 324-335 ◽  
Author(s):  
Gregg B. Nyberg ◽  
R. Robert Balcarcel ◽  
Brian D. Follstad ◽  
Gregory Stephanopoulos ◽  
Daniel I. C. Wang
Keyword(s):  
Amino Acids ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Complex Medium ◽  
Ovary Cells

Biosynthesis and intracellular post-translational processing of normal and mutant platelet glycoprotein GPIb-IX

2001 ◽  
Vol 358 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Philippe ULSEMER ◽  
Catherine STRASSEL ◽  
Marie-Jeanne BAAS ◽  
Jean SALAMERO ◽  
Sylvette CHASSEROT-GOLAZ ◽  
...  
Keyword(s):  
Cell Surface ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Brefeldin A ◽  
Surface Expression ◽  
Platelet Glycoprotein ◽  
Ovary Cells ◽  
Confocal Immunofluorescence Microscopy ◽  
Vessel Injury ◽  
Von Willebrand

The multisubunit leucine-rich glycoprotein (GP) Ib–IX–V complex mediates von Willebrand factor-dependent platelet adhesion at sites of blood-vessel injury. Molecular defects of this receptor are reported to cause the Bernard–Soulier haemorrhagic disorder. To gain insight into the mechanisms controlling expression of normal and defective receptors, we performed pulse–chase metabolic studies and detailed analysis of intracellular processing in GPIb-IX-transfected Chinese-hamster ovary cells. In the native complex, after early subunit association, sugars N-linked to the three subunits are trimmed and sialylated in the Golgi compartment and GPIbα undergoes extensive O-glycosylation. Surface biotinylation during chase demonstrated that only fully processed complexes reach the cell surface. Tunicamycin treatment revealed that early N-glycosylation is not required for O-glycosylation of GPIbα and surface expression of the complex. Biosynthetic studies were then performed on a Bernard–Soulier variant based on previous description of abnormal GPIbα size and decreased surface expression. The mutant complex associated normally, but displayed defective processing of its N-linked sugars and abnormal O-glycosylation of GPIbα. Confocal immunofluorescence microscopy revealed that the mutant complexes could reach the cell surface but also accumulated intracellularly, while use of compartment specific markers showed strong co-localization in the endoplasmic reticulum (ER) and ER-to-Golgi intermediate compartments (‘ERGIC’) and only slight labelling of the cis-Golgi. Blockade before the Golgi was confirmed by brefeldin A treatment, which restored O-glycosylation and processing of N-linked sugars. The present study has shown that transfer from the ER to the Golgi represents an important step for controlling post-translational processing and surface expression of normal GPIb-IX-V complex.

scholarly journals Characterization of Neuropeptide B (NPB), Neuropeptide W (NPW), and Their Receptors in Chickens: Evidence for NPW Being a Novel Inhibitor of Pituitary GH and Prolactin Secretion

Endocrinology ◽  
2016 ◽  
Vol 157 (9) ◽  
pp. 3562-3576 ◽  
Author(s):  
Guixian Bu ◽  
Dongliang Lin ◽  
Lin Cui ◽  
Long Huang ◽  
Can Lv ◽  
...  
Keyword(s):  
Amino Acids ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Prolactin Secretion ◽  
Luciferase Reporter ◽  
Intracellular Camp ◽  
Pituitary Cells ◽  
Reporter System ◽  
Ovary Cells ◽  
The Central Nervous System

The 2 structurally and functionally related peptides, neuropeptide B (NPB) and neuropeptide W (NPW), together with their receptor(s) (NPBWR1/NPBWR2) constitute the NPB/NPW system, which acts mainly on the central nervous system to regulate many physiological processes in mammals. However, little is known about this NPB/NPW system in nonmammalian vertebrates. In this study, the functionality and expression of this NPB/NPW system and its actions on the pituitary were investigated in chickens. The results showed that: 1) chicken NPB/NPW system comprises an NPB peptide of 28 amino acids (cNPB28), an NPW peptide of 23 or 30 amino acids (cNPW23/cNPW30), and their 2 receptors (cNPBWR1 and cNPBWR2), which are highly homologous to their human counterparts. 2) Using a pGL3-CRE-luciferase reporter system, we demonstrated that cNPBWR2 expressed in Chinese hamster ovary cells can be potently activated by cNPW23 (not cNPB28), and its activation inhibits the intracellular cAMP signaling pathway, whereas cNPBWR1 shows no response to peptide treatment, suggesting a crucial role of cNPBWR2 in mediating cNPW/cNPB actions. 3) Quantitative real-time PCR revealed that cNPW and cNPB are widely expressed in chicken tissues, including hypothalamus, whereas cNPBWR1 and cNPBWR2 are mainly expressed in brain or pituitary. 4) In accordance with abundant cNPBWR2 expression in pituitary, cNPW23 could dose dependently inhibit GH and prolactin secretion induced by GHRH and vasoactive intestinal polypeptide, respectively, in cultured chick pituitary cells, as monitored by Western blotting. Collectively, our data reveal a functional NPB/NPW system in birds and offer the first proof that NPW can act directly on pituitary to inhibit GH/prolactin secretion in vertebrates.

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