scholarly journals Differential Induction of Two p24δ Putative Cargo Receptors upon Activation of a Prohormoneproducing Cell

2000 ◽  
Vol 11 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Roland P. Kuiper ◽  
Hans R. Waterham ◽  
Jutta Rötter ◽  
Gerrit Bouw ◽  
Gerard J. M. Martens
Keyword(s):  
Secretory Pathway ◽  
Protein Transport ◽  
Fold Increase ◽  
Type I ◽  
Black Background ◽  
Background Adaptation ◽  
Cargo Transport ◽  
Transport Vesicles ◽  
Identification And Characterization

The p24 family consists of type I transmembrane proteins that are present abundantly in transport vesicles, may play a role in endoplasmic reticulum-to-Golgi cargo transport, and have been classified into subfamilies named p24α, -β, -γ, and -δ. We previously identified a member of the p24δ subfamily that is coordinately expressed with the prohormone proopiomelanocortin (POMC) in the melanotrope cells of the intermediate pituitary during black background adaptation of the amphibian Xenopus laevis(∼30-fold increase in POMC mRNA). In this study, we report on the characterization of this p24δ member (Xp24δ2) and on the identification and characterization of a second member (Xp24δ1) that is also expressed in the melanotrope cells and that has 66% amino acid sequence identity to Xp24δ2. The two p24δ members are ubiquitously expressed, but Xp24δ2 is neuroendocrine enriched. During black background adaptation, the amount of the Xp24δ2 protein in the intermediate pituitary was increased ∼25 times, whereas Xp24δ1 protein expression was increased only 2.5 times. Furthermore, the level of Xp24δ2 mRNA was ∼5-fold higher in the melanotrope cells of black-adapted animals than in those of white-adapted animals, whereas Xp24δ1 mRNA expression was not induced. Therefore, the expression of Xp24δ2specifically correlates with the expression of POMC. Together, our findings suggest that p24δ proteins have a role in selective protein transport in the secretory pathway.

Cell-type-specific and selectively induced expression of members of the p24 family of putative cargo receptors

2002 ◽  
Vol 115 (5) ◽  
pp. 1049-1058 ◽  
Author(s):  
Jutta Rötter ◽  
Roland P. Kuiper ◽  
Gerrit Bouw ◽  
Gerard J. M. Martens
Keyword(s):  
Secretory Pathway ◽  
Protein Transport ◽  
Type I ◽  
Pituitary Cells ◽  
Cell Type ◽  
Biosynthetic Activity ◽  
Highly Active ◽  
Transport Vesicles ◽  
Cell Type Specific ◽  
P24 Proteins

Members of the p24 family of type I transmembrane proteins are highly abundant in transport vesicles and are thought to be involved in selective protein transport between the endoplasmic reticulum and the Golgi complex. The p24 proteins have been grouped into four subfamilies (α, β,γ, and δ) and appear to assemble into tetrameric complexes that contain only one representative from each subfamily. Here we molecularly dissected the p24 family in a single cell type, namely in the intermediate pituitary melanotrope cells of the amphibian Xenopus laevis. The biosynthetic activity of these cells for production of their major cargo protein proopiomelanocortin (POMC) can be physiologically manipulated via the process of background adaptation (∼30-fold induction, with highly active cells in black toads and virtually inactive cells in white animals). Extensive cDNA library screening revealed the identity of six p24 proteins expressed in the Xenopus melanotrope cells, namely one member of the p24α(α3), one of the p24β (β1), two of the p24γ (γ2, γ3) and two of the p24δ (δ1, δ2) subfamily. Two other Xenopus p24 proteins, Xp24α2 and-γ1, were not expressed in the melanotrope cells, pointing to cell-type specific p24 expression. Of the six melanotrope p24 proteins, the expression of four (Xp24α3, -β1,-γ3 and -δ2) was 20- to 30-fold induced in active versus inactive melanotropes, whereas that of the other two members(Xp24γ2 and -δ1) had not or only slightly increased. The four proteins were induced only in the intermediate melanotrope cells and not in the anterior pituitary cells, and displayed similar overall tissue distributions that differed from those of Xp24γ1,-γ2 and -δ1. Together, our results reveal that p24 expression can be cell-type specific and selectively induced, and suggest that in Xenopus melanotrope cells anα 3/β1/γ3/δ2p24 complex is involved in POMC transport through the early stages of the secretory pathway.

scholarly journals Yos1p Is a Novel Subunit of the Yip1p–Yif1p Complex and Is Required for Transport between the Endoplasmic Reticulum and the Golgi Complex

2005 ◽  
Vol 16 (4) ◽  
pp. 1673-1683 ◽  
Author(s):  
Matthew Heidtman ◽  
Catherine Z. Chen ◽  
Ruth N. Collins ◽  
Charles Barlowe
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Secretory Pathway ◽  
Integral Membrane Protein ◽  
Rab Gtpases ◽  
Reading Frame ◽  
Multicopy Suppressor ◽  
Transport Vesicles ◽  
Identification And Characterization

Yeast Yip1p is a member of a conserved family of transmembrane proteins that interact with Rab GTPases. Previous studies also have indicated a role for Yip1p in the biogenesis of endoplasmic reticulum (ER)-derived COPII transport vesicles. In this report, we describe the identification and characterization of the uncharacterized open reading frame YER074W-A as a novel multicopy suppressor of the thermosensitive yip1-4 strain. We have termed this gene Yip One Suppressor 1 (YOS1). Yos1p is essential for growth and for function of the secretory pathway; depletion or inactivation of Yos1p blocks transport between the ER and the Golgi complex. YOS1 encodes an integral membrane protein of 87 amino acids that is conserved in eukaryotes. Yos1p localizes to ER and Golgi membranes and is efficiently packaged into ER-derived COPII transport vesicles. Yos1p associates with Yip1p and Yif1p, indicating Yos1p is a novel subunit of the Yip1p–Yif1p complex.

scholarly journals A Cell-Specific Transgenic Approach in Xenopus Reveals the Importance of a Functional p24 System for a Secretory Cell

2004 ◽  
Vol 15 (3) ◽  
pp. 1244-1253 ◽  
Author(s):  
Gerrit Bouw ◽  
Rick Van Huizen ◽  
Eric J.R. Jansen ◽  
Gerard J.M. Martens
Keyword(s):  
Secretory Pathway ◽  
Protein Transport ◽  
Transgenic Animal ◽  
Secretory Protein ◽  
Physiological Effect ◽  
Early Secretory Pathway ◽  
Golgi Transport ◽  
Cargo Transport ◽  
Transport Vesicles ◽  
A Cell

The p24α, -β, -γ, and -δ proteins are major multimeric constituents of cycling endoplasmic reticulum-Golgi transport vesicles and are thought to be involved in protein transport through the early secretory pathway. In this study, we targeted transgene overexpression of p24δ2 specifically to the Xenopus intermediate pituitary melanotrope cell that is involved in background adaptation of the animal and produces high levels of its major secretory cargo proopiomelanocortin (POMC). The transgene product effectively displaced the endogenous p24 proteins, resulting in a melanotrope cell p24 system that consisted predominantly of the transgene p24δ2 protein. Despite the severely distorted p24 machinery, the subcellular structures as well as the level of POMC synthesis were normal in these cells. However, the number and pigment content of skin melanophores were reduced, impairing the ability of the transgenic animal to fully adapt to a black background. This physiological effect was likely caused by the affected profile of POMC-derived peptides observed in the transgenic melanotrope cells. Together, our results suggest that in the early secretory pathway an intact p24 system is essential for efficient secretory cargo transport or for supplying cargo carriers with the correct protein machinery to allow proper secretory protein processing.

scholarly journals IDUA mutational profiling of a cohort of 102 European patients with mucopolysaccharidosis type I: identification and characterization of 35 novel α-L-iduronidase (IDUA) alleles

2011 ◽  
Vol 32 (6) ◽  
pp. E2189-E2210 ◽  
Author(s):  
Francesca Bertola ◽  
Mirella Filocamo ◽  
Giorgio Casati ◽  
Matthew Mort ◽  
Camillo Rosano ◽  
...  
Keyword(s):  
Type I ◽  
Mucopolysaccharidosis Type ◽  
Mucopolysaccharidosis Type I ◽  
Mutational Profiling ◽  
Identification And Characterization

scholarly journals Identification and characterization of two novel mutations in the LPL gene causing type I hyperlipoproteinemia

2016 ◽  
Vol 252 ◽  
pp. e73-e74
Author(s):  
P. Pingitore ◽  
S.M. Lepore ◽  
C. Pirazzi ◽  
R.M. Mancina ◽  
B.M. Motta ◽  
...  
Keyword(s):  
Type I ◽  
Novel Mutations ◽  
Lpl Gene ◽  
Identification And Characterization

Identification and characterization of a heat-labile type I glutamine synthetase fromStreptomyces cinnamonensis

1997 ◽  
Vol 42 (5) ◽  
pp. 431-440 ◽  
Author(s):  
K. T. Nguyen ◽  
L. T. Nguyen ◽  
O. Benada ◽  
V. Běhal
Keyword(s):  
Glutamine Synthetase ◽  
Type I ◽  
Heat Labile ◽  
Identification And Characterization

Identification and characterization of 20 novel pathogenic variants in 60 unrelated Indian patients with mucopolysaccharidoses type I and type II

2016 ◽  
Vol 90 (6) ◽  
pp. 496-508 ◽  
Author(s):  
A. Uttarilli ◽  
P. Ranganath ◽  
D. Matta ◽  
J. Md Nurul Jain ◽  
K. Prasad ◽  
...  
Keyword(s):  
Type I ◽  
Type Ii ◽  
Pathogenic Variants ◽  
Indian Patients ◽  
Identification And Characterization

scholarly journals Identification and Characterization of the Asperthecin Gene Cluster of Aspergillus nidulans

2008 ◽  
Vol 74 (24) ◽  
pp. 7607-7612 ◽  
Author(s):  
Edyta Szewczyk ◽  
Yi-Ming Chiang ◽  
C. Elizabeth Oakley ◽  
Ashley D. Davidson ◽  
Clay C. C. Wang ◽  
...  
Keyword(s):  
Secondary Metabolite ◽  
Polyketide Synthase ◽  
Gene Clusters ◽  
Laboratory Culture ◽  
Culture Conditions ◽  
Type I ◽  
Genes Encoding ◽  
Identification And Characterization ◽  
Normal Laboratory

ABSTRACT The sequencing of Aspergillus genomes has revealed that the products of a large number of secondary metabolism pathways have not yet been identified. This is probably because many secondary metabolite gene clusters are not expressed under normal laboratory culture conditions. It is, therefore, important to discover conditions or regulatory factors that can induce the expression of these genes. We report that the deletion of sumO, the gene that encodes the small ubiquitin-like protein SUMO in A. nidulans, caused a dramatic increase in the production of the secondary metabolite asperthecin and a decrease in the synthesis of austinol/dehydroaustinol and sterigmatocystin. The overproduction of asperthecin in the sumO deletion mutant has allowed us, through a series of targeted deletions, to identify the genes required for asperthecin synthesis. The asperthecin biosynthesis genes are clustered and include genes encoding an iterative type I polyketide synthase, a hydrolase, and a monooxygenase. The identification of these genes allows us to propose a biosynthetic pathway for asperthecin.

scholarly journals Identification and characterization of two novel mutations in the LPL gene causing type I hyperlipoproteinemia

2016 ◽  
Vol 10 (4) ◽  
pp. 816-823 ◽  
Author(s):  
Piero Pingitore ◽  
Saverio Massimo Lepore ◽  
Carlo Pirazzi ◽  
Rosellina Margherita Mancina ◽  
Benedetta Maria Motta ◽  
...  
Keyword(s):  
Type I ◽  
Novel Mutations ◽  
Lpl Gene ◽  
Identification And Characterization
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