Search results for "Secretory"
showing 10 items of 150 documents
Persistent Tachypnea of Infancy. Usual and Aberrant.
2016
Persistent tachypnea of infancy (PTI) is a specific clinical entity of undefined etiology comprising the two diseases neuroendocrine cell hyperplasia of infancy (NEHI) and pulmonary interstitial glycogenosis. The outcome of typical NEHI is favorable. The outcome may be different for patients without a typical NEHI presentation, and thus a lung biopsy to differentiate the diseases is indicated.To determine whether infants with the characteristic clinical presentation and computed tomographic (CT) imaging of NEHI (referred to as "usual PTI") have long-term outcome and biopsy findings similar to those of infants with an aberrant presentation and/or with additional localized minor CT findings (…
The ER-Membrane Transport System Is Critical for Intercellular Trafficking of the NSm Movement Protein and Tomato Spotted Wilt Tospovirus.
2015
Plant viruses move through plasmodesmata to infect new cells. The plant endoplasmic reticulum (ER) is interconnected among cells via the ER desmotubule in the plasmodesma across the cell wall, forming a continuous ER network throughout the entire plant. This ER continuity is unique to plants and has been postulated to serve as a platform for the intercellular trafficking of macromolecules. In the present study, the contribution of the plant ER membrane transport system to the intercellular trafficking of the NSm movement protein and Tomato spotted wilt tospovirus (TSWV) is investigated. We showed that TSWV NSm is physically associated with the ER membrane in Nicotiana benthamiana plants. An…
In vivo Trafficking and Localization of p24 Proteins in Plant Cells
2008
p24 proteins constitute a family of putative cargo receptors that traffic in the early secretory pathway. p24 proteins can be divided into four subfamilies (p23, p24, p25 and p26) by sequence homology. In contrast to mammals and yeast, most plant p24 proteins contain in their cytosolic C-terminus both a dilysine motif in the -3, -4 position and a diaromatic motif in the -7, -8 position. We have previously shown that the cytosolic tail of Arabidopsis p24 proteins has the ability to interact with ARF1 and coatomer (through the dilysine motif) and with COPII subunits (through the diaromatic motif). Here, we establish the localization and trafficking properties of an Arabidopsis thaliana p24 pr…
Ultrastructure of posterior sternal glands of Macrotermes annandalei (Silvestri): new members of the sexual glandular set found in termites (Insecta).
2004
In female alates of Macrotermes annandalei, two types of abdominal glands are involved in the secretion of sex pheromone. Tergal glands are found at the anterior margin of tergites 6-10 and posterior sternal glands (PSGs) are located at the anterior margin of sternites 6-7. The cytological features of both types of glands are quite similar. The fine structural organization of PSGs is studied more precisely and described for the first time. The glandular cuticle is pitted with narrow apertures corresponding to the openings of numerous subcuticular pouches. Several Class 3 glandular units open in each pouch. One canal cell and one secretory cell make an individual glandular unit. The canal ce…
Membrane protein integration into the endoplasmic reticulum
2011
Most integral membrane proteins are targeted, inserted and assembled in the endoplasmic reticulum membrane. The sequential and potentially overlapping events necessary for membrane protein integration take place at sites termed translocons, which comprise a specific set of membrane proteins acting in concert with ribosomes and, probably, molecular chaperones to ensure the success of the whole process. In this minireview, we summarize our current understanding of helical membrane protein integration at the endoplasmic reticulum, and highlight specific characteristics that affect the biogenesis of multispanning membrane proteins.
Distribution and coexistence of chromogranin A-, serotonin-and pancreastatin-like immunoreactivity in endocrine-like cells of the human anal canal
1992
The comparative distribution and coexistence of chromogranin A (CGA)-, serotonin (5-hydroxytryptamine; 5-HT)- and pancreastatin (PST)-like immunoreactivity in endocrine-like cells of the human anal canal was investigated by light-microscopic immunocytochemistry. The largest population of colorectal endocrine-like cells consisted of CGA-immunoreactive (ir) cells, followed by the 5-HT-ir and PST-ir cell population. In the anal transitional zone (ATZ), CGA- and 5-HT-immunoreactivity was equally distributed; ir-PST was confined to a smaller endocrine-like cell population. In the squamous zone and the perianal skin, Merkel cells in the basal layer of the epidermis and hair follicles exhibited ir…
Shedding of Membrane Vesicles Mediates Fibroblast Growth Factor-2 Release from Cells
2003
Fibroblast growth factor-2 (FGF-2), a polypeptide with regulatory activity on cell growth and differentiation, lacks a conventional secretory signal sequence, and its mechanism of release from cells remains unclear. We characterized the role of extracellular vesicle shedding in FGF-2 release. Viable cells released membrane vesicles in the presence of serum. However, in serum-free medium vesicle shedding was dramatically down-regulated, and the cells did not release FGF-2 activity into their conditioned medium. Addition of serum to serum-starved cells rapidly induced intracellular FGF-2 clustering under the plasma membrane and into granules that colocalized with patches of the cell membrane …
Apical transport of osteopontin is independent of N-glycosylation and sialylation.
2002
Studies of how epithelial surface polarity into apical and basolateral domains is generated and maintained have proposed that carbohydrate modifications serve as apical targeting signals for proteins by interacting with lectin sorters. However, the experimental evidence in support of N-glycans, O-glycans and sialic acids mediating apical transport is still very controversial. This could be partly due to the fact that in most studies exogenously expressed proteins were analysed. One has, therefore, examined the role of carbohydrate moieties in apical targeting of the endogenous secretory protein osteopontin in MDCK cells. It was found, however, that sorting of osteopontin does not require N-…
Coping with competition: neuroendocrine responses and cognitive variables.
2008
Confronting another individual or group motivated by the same goal is a very frequent situation in human communities that occurs in many other species. Competitive interactions emerge as critical situations that shed light on the effects and consequences of social stress on health. But more important than the situation itself is the way it is interpreted by the subject. This "appraisal" involves cognitive processes that contribute to explaining the neuroendocrine response to these interactions, helping to understanding the vulnerability or resistance to their effects. In this review, we defend the need to study human competition within the social stress framework, while maintaining an evolu…
Synaptobrevin cleavage by the tetanus toxin light chain is linked to the inhibition of exocytosis in chromaffin cells
1994
AbstractExocytosis of secretory granules by adrenal chromaffin cells is blocked by the tetanus toxin light chain in a zinc specific manner. Here we show that cellular synaptobrevin is almost completely degraded by the tetanus toxin light chain within 15 min. We used highly purified adrenal secretory granules to show that synaptobrevin, which can be cleaved by the tetanus toxin light chain, is localized in the vesicular membrane. Proteolysis of synaptobrevin in cells and in secretory granules is reversibly inhibited by the zinc chelating agent dipicolinic acid. Moreover, cleavage of synaptobrevin present in secretory granules by the tetanus toxin light chain is blocked by the zinc peptidase …