scholarly journals Protein secretion and secreted proteins in pathogenicNeisseriaceae

2006 ◽  
Vol 30 (2) ◽  
pp. 292-319 ◽  
Author(s):  
Peter Van Ulsen ◽  
Jan Tommassen
Keyword(s):  
Protein Secretion ◽  
Secreted Proteins

scholarly journals The Emerging Mechanisms of Wnt Secretion and Signaling in Development

2021 ◽  
Vol 9 ◽  
Author(s):  
Shefali Mehta ◽  
Swapnil Hingole ◽  
Varun Chaudhary
Keyword(s):  
Signaling Pathways ◽  
Protein Secretion ◽  
Extracellular Space ◽  
Tissue Homeostasis ◽  
Secreted Proteins ◽  
Complex Interplay ◽  
The Past ◽  
Signaling Mechanisms ◽  
Protein Gradients ◽  
Multiple Signaling

Wnts are highly-conserved lipid-modified secreted proteins that activate multiple signaling pathways. These pathways regulate crucial processes during various stages of development and maintain tissue homeostasis in adults. One of the most fascinating aspects of Wnt protein is that despite being hydrophobic, they are known to travel several cell distances in the extracellular space. Research on Wnts in the past four decades has identified several factors and uncovered mechanisms regulating their expression, secretion, and mode of extracellular travel. More recently, analyses on the importance of Wnt protein gradients in the growth and patterning of developing tissues have recognized the complex interplay of signaling mechanisms that help in maintaining tissue homeostasis. This review aims to present an overview of the evidence for the various modes of Wnt protein secretion and signaling and discuss mechanisms providing precision and robustness to the developing tissues.

scholarly journals The Road Less Traveled? Unconventional Protein Secretion at Parasite–Host Interfaces

2021 ◽  
Vol 9 ◽  
Author(s):  
Erina A. Balmer ◽  
Carmen Faso
Keyword(s):  
Protein Secretion ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Cell Model ◽  
Signal Sequence ◽  
Model Organism ◽  
Secreted Proteins ◽  
Current Status ◽  
Secretory Proteins ◽  
Secretion Pathways

Protein secretion in eukaryotic cells is a well-studied process, which has been known for decades and is dealt with by any standard cell biology textbook. However, over the past 20 years, several studies led to the realization that protein secretion as a process might not be as uniform among different cargos as once thought. While in classic canonical secretion proteins carry a signal sequence, the secretory or surface proteome of several organisms demonstrated a lack of such signals in several secreted proteins. Other proteins were found to indeed carry a leader sequence, but simply circumvent the Golgi apparatus, which in canonical secretion is generally responsible for the modification and sorting of secretory proteins after their passage through the endoplasmic reticulum (ER). These alternative mechanisms of protein translocation to, or across, the plasma membrane were collectively termed “unconventional protein secretion” (UPS). To date, many research groups have studied UPS in their respective model organism of choice, with surprising reports on the proportion of unconventionally secreted proteins and their crucial roles for the cell and survival of the organism. Involved in processes such as immune responses and cell proliferation, and including far more different cargo proteins in different organisms than anyone had expected, unconventional secretion does not seem so unconventional after all. Alongside mammalian cells, much work on this topic has been done on protist parasites, including genera Leishmania, Trypanosoma, Plasmodium, Trichomonas, Giardia, and Entamoeba. Studies on protein secretion have mainly focused on parasite-derived virulence factors as a main source of pathogenicity for hosts. Given their need to secrete a variety of substrates, which may not be compatible with canonical secretion pathways, the study of mechanisms for alternative secretion pathways is particularly interesting in protist parasites. In this review, we provide an overview on the current status of knowledge on UPS in parasitic protists preceded by a brief overview of UPS in the mammalian cell model with a focus on IL-1β and FGF-2 as paradigmatic UPS substrates.

scholarly journals RAB6 and microtubules restrict protein secretion to focal adhesions

2019 ◽  
Vol 218 (7) ◽  
pp. 2215-2231 ◽  
Author(s):  
Lou Fourriere ◽  
Amal Kasri ◽  
Nelly Gareil ◽  
Sabine Bardin ◽  
Hugo Bousquet ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Protein Secretion ◽  
Golgi Complex ◽  
Essential Role ◽  
Focal Adhesions ◽  
Secreted Proteins ◽  
Cell Compartments ◽  
Secretion Assay

To ensure their homeostasis and sustain differentiated functions, cells continuously transport diverse cargos to various cell compartments and in particular to the cell surface. Secreted proteins are transported along intracellular routes from the endoplasmic reticulum through the Golgi complex before reaching the plasma membrane along microtubule tracks. Using a synchronized secretion assay, we report here that exocytosis does not occur randomly at the cell surface but on localized hotspots juxtaposed to focal adhesions. Although microtubules are involved, the RAB6-dependent machinery plays an essential role. We observed that, irrespective of the transported cargos, most post-Golgi carriers are positive for RAB6 and that its inactivation leads to a broad reduction of protein secretion. RAB6 may thus be a general regulator of post-Golgi secretion.

scholarly journals Type V Protein Secretion Pathway: the Autotransporter Story

2004 ◽  
Vol 68 (4) ◽  
pp. 692-744 ◽  
Author(s):  
Ian R. Henderson ◽  
Fernando Navarro-Garcia ◽  
Mickaël Desvaux ◽  
Rachel C. Fernandez ◽  
Dlawer Ala'Aldeen
Keyword(s):  
Protein Secretion ◽  
Bacterial Infections ◽  
Protein Translocation ◽  
Research Field ◽  
Secreted Proteins ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
V Protein ◽  
Secretion Pathway ◽  
Type V

SUMMARY Gram-negative bacteria possess an outer membrane layer which constrains uptake and secretion of solutes and polypeptides. To overcome this barrier, bacteria have developed several systems for protein secretion. The type V secretion pathway encompasses the autotransporter proteins, the two-partner secretion system, and the recently described type Vc or AT-2 family of proteins. Since its discovery in the late 1980s, this family of secreted proteins has expanded continuously, due largely to the advent of the genomic age, to become the largest group of secreted proteins in gram-negative bacteria. Several of these proteins play essential roles in the pathogenesis of bacterial infections and have been characterized in detail, demonstrating a diverse array of function including the ability to condense host cell actin and to modulate apoptosis. However, most of the autotransporter proteins remain to be characterized. In light of new discoveries and controversies in this research field, this review considers the autotransporter secretion process in the context of the more general field of bacterial protein translocation and exoprotein function.

Protein synthesis and secretion by the epididymis of the tammar wallaby, Macropus eugenii (Macropodidae: Marsupialia)

1992 ◽  
Vol 4 (5) ◽  
pp. 533 ◽  
Author(s):  
G Chaturapanich ◽  
RC Jones ◽  
J Clulow
Keyword(s):  
Protein Synthesis ◽  
Protein Secretion ◽  
Tammar Wallaby ◽  
Secreted Proteins ◽  
Blood Proteins ◽  
Macropus Eugenii ◽  
Cauda Epididymidis

The objectives were to assess the following in a marsupial: which proteins are synthesized by the different regions of the epididymis and secreted into the lumen of the ductus; the effect of the experimental method on the detection of protein secretion; the role of the testis in regulating the protein synthesis and secretion; and whether any of the secreted proteins may associate with spermatozoa. Samples from untreated animals were collected for examination by perfusing Krebs-bicarbonate through the ductus epididymidis in vivo (microperfusion), and after incorporation of [35S]methionine during incubation of minced duct in vitro. Electrophoresis of the samples showed that the caput and corpus epididymidis (initial segments) secreted most of the proteins that were synthesized and secreted by the epididymal mucosa, and that the cauda epididymidis secreted mainly blood proteins. Also, many more proteins were secreted in vitro than into the microperfusates in vivo, or were found by Jones (1987) in micropuncture samples of epididymal plasma. The synthesis and secretion of five proteins was androgen dependent (M(r) 75,700, 30,000, 18,700, 17,400 and 12,800). Also, the luminal fluids from the testis stimulated the secretion of two proteins (M(r) 46,300 and 36,100) and inhibited the secretion of three proteins (M(r) 43,000, 32,300 and 21,400). Examination of detergent extracts of spermatozoa indicated that they lose three proteins (M(r) 28,000, 30,000 and 47,000) and gain one (M(r) 30,400) during passage through the epididymis. The method of determining protein secretion affected the findings. Protein secretion, its control and its association with spermatozoa are broadly similar in the tammar wallaby to the processes described in eutherian mammals.

scholarly journals Infection-Blocking Genes of a Symbiotic Rhizobium leguminosarum Strain That Are Involved in Temperature-Dependent Protein Secretion

2003 ◽  
Vol 16 (1) ◽  
pp. 53-64 ◽  
Author(s):  
M. R. Bladergroen ◽  
K. Badelt ◽  
H. P. Spaink
Keyword(s):  
Nitrogen Fixation ◽  
Protein Secretion ◽  
Rhizobium Leguminosarum ◽  
Signal Sequence ◽  
Gene Clusters ◽  
Secreted Proteins ◽  
Type I ◽  
Secretion Systems ◽  
Temperature Dependent ◽  
Animal Pathogens

Rhizobium leguminosarum strain RBL5523 is able to form nodules on pea, but these nodules are ineffective for nitrogen fixation. The impairment in nitrogen fixation appears to be caused by a defective infection of the host plant and is host specific for pea. A Tn5 mutant of this strain, RBL5787, is able to form effective nodules on pea. We have sequenced a 33-kb region around the phage-transductable Tn5 insertion. The Tn5 insertion was localized to the 10th gene of a putative operon of 14 genes that was called the imp (impaired in nitrogen fixation) locus. Several highly similar gene clusters of unknown function are present in Pseudomonas aeruginosa, Vibrio cholerae, Edwardsiella ictaluri, and several other animal pathogens. Homology studies indicate that several genes of the imp locus are involved in protein phosphorylation, either as a kinase or dephosphorylase, or contain a phosphoprotein-binding module called a forkhead-associated domain. Other proteins show similarity to proteins involved in type III protein secretion. Two dimensional gel electrophoretic analysis of the secreted proteins in the supernatant fluid of cultures of RBL5523 and RBL5787 showed the absence in the mutant strain of at least four proteins with molecular masses of approximately 27 kDa and pIs between 5.5 and 6.5. The production of these proteins in the wild-type strain is temperature dependent. Sequencing of two of these proteins revealed that their first 20 amino acids are identical. This sequence showed homology to that of secreted ribose binding proteins (RbsB) from Bacilus subtilis and V. cholerae. Based on this protein sequence, the corresponding gene encoding a close homologue of RbsB was cloned that contains a N-terminal signal sequence that is recognized by type I secretion systems. Inoculation of RBL5787 on pea plants in the presence of supernatant of RBL5523 caused a reduced ability of RBL5787 to nodulate pea and fix nitrogen. Boiling of this supernatant before inoculation restored the formation of effective nodules to the original values, indicating that secreted proteins are indeed responsible for the impaired phenotype. These data suggest that the imp locus is involved in the secretion to the environment of proteins, including periplasmic RbsB protein, that cause blocking of infection specifically in pea plants.

scholarly journals Overexpression of the Gene Encoding GTP:Mannose-1-Phosphate Guanyltransferase, mpg1, Increases Cellular GDP-Mannose Levels and Protein Mannosylation in Trichoderma reesei

2003 ◽  
Vol 69 (8) ◽  
pp. 4383-4389 ◽  
Author(s):  
Anna Zakrzewska ◽  
Grazyna Palamarczyk ◽  
Hubert Krotkiewski ◽  
Ewa Zdebska ◽  
Markku Saloheimo ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Protein Secretion ◽  
Protein Glycosylation ◽  
Secreted Proteins ◽  
Regulatory Role ◽  
Limiting Factors ◽  
Hypocrea Jecorina ◽  
Gene Encoding ◽  
Twofold Increase ◽  
Dolichyl Phosphate

ABSTRACT To elucidate the regulation and limiting factors in the glycosylation of secreted proteins, the mpg1 and dpm1 genes from Trichoderma reesei (Hypocrea jecorina) encoding GTP:α-d-mannose-1-phosphate guanyltransferase and dolichyl phosphate mannose synthase (DPMS), respectively, were overexpressed in T. reesei. No significant increases were observed in DPMS activity or protein secretion in dpm1-overexpressing transformants, whereas overexpression of mpg1 led to a twofold increase in GDP-mannose (GDPMan) levels. GDPMan was effectively utilized by mannnosyltransferases and resulted in hypermannosylation of secreted proteins in both N and O glycosylation. Overexpression of the mpg1 gene also increased the transcription of the dpm1 gene and DPMS activity. Our data indicate that the level of cellular GDPMan can play a major regulatory role in protein glycosylation in T. reesei.

scholarly journals Degradation of Extracytoplasmic Catalysts for Protein Folding in Bacillus subtilis

2013 ◽  
Vol 80 (4) ◽  
pp. 1463-1468 ◽  
Author(s):  
Laxmi Krishnappa ◽  
Carmine G. Monteferrante ◽  
Jolanda Neef ◽  
Annette Dreisbach ◽  
Jan Maarten van Dijl
Keyword(s):  
Quality Control ◽  
Protein Folding ◽  
Bacillus Subtilis ◽  
Membrane Proteins ◽  
Protein Secretion ◽  
Secreted Proteins ◽  
Biotechnological Production ◽  
Content Type ◽  
Wide Range ◽  
Mutant Strains

ABSTRACTThe general protein secretion pathway ofBacillus subtilishas a high capacity for protein export from the cytoplasm, which is exploited in the biotechnological production of a wide range of enzymes. These exported proteins pass the membrane in an unfolded state, and accordingly, they have to fold into their active and protease-resistant conformations once membrane passage is completed. The lipoprotein PrsA and the membrane proteins HtrA and HtrB facilitate the extracytoplasmic folding and quality control of exported proteins. Among the native exported proteins ofB. subtilisare at least 10 proteases that have previously been implicated in the degradation of heterologous secreted proteins. Recently, we have shown that these proteases also degrade many native membrane proteins, lipoproteins, and secreted proteins. The present studies were therefore aimed at assessing to what extent these proteases also degrade extracytoplasmic catalysts for protein folding. To this end, we employed a collection of markerless protease mutant strains that lack up to 10 different extracytoplasmic proteases. The results show that PrsA, HtrA, and HtrB are indeed substrates of multiple extracytoplasmic proteases. Thus, improved protein secretion by multiple-protease-mutant strains may be related to both reduced proteolysis and improved posttranslocational protein folding and quality control.

scholarly journals Advances and perspectives in discovery and functional analysis of small secreted proteins in plants

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiao-Li Hu ◽  
Haiwei Lu ◽  
Md Mahmudul Hassan ◽  
Jin Zhang ◽  
Guoliang Yuan ◽  
...  
Keyword(s):  
Plant Species ◽  
Protein Secretion ◽  
Functional Characterization ◽  
Secreted Proteins ◽  
Computational Algorithms ◽  
Biotic Stresses ◽  
Substantial Progress ◽  
Microbe Interactions ◽  
Secretion Pathways ◽  
Small Secreted Proteins

AbstractSmall secreted proteins (SSPs) are less than 250 amino acids in length and are actively transported out of cells through conventional protein secretion pathways or unconventional protein secretion pathways. In plants, SSPs have been found to play important roles in various processes, including plant growth and development, plant response to abiotic and biotic stresses, and beneficial plant–microbe interactions. Over the past 10 years, substantial progress has been made in the identification and functional characterization of SSPs in several plant species relevant to agriculture, bioenergy, and horticulture. Yet, there are potentially a lot of SSPs that have not been discovered in plant genomes, which is largely due to limitations of existing computational algorithms. Recent advances in genomics, transcriptomics, and proteomics research, as well as the development of new computational algorithms based on machine learning, provide unprecedented capabilities for genome-wide discovery of novel SSPs in plants. In this review, we summarize known SSPs and their functions in various plant species. Then we provide an update on the computational and experimental approaches that can be used to discover new SSPs. Finally, we discuss strategies for elucidating the biological functions of SSPs in plants.

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