Sexual and reproductive health outcomes for forcibly displaced persons living in urban environments in low- and middle-income countries: a scoping review protocol.

OBJECTIVE: The objective of this review is to characterize the state of literature regarding forcibly displaced persons' sexual and reproductive health in urban areas in low- and middle-income countries. Specific objectives include describing the sexual and reproductive health outcomes among forcibly displaced persons relocating in urban environments. INTRODUCTION: As a result of persecution, conflict, violence, human rights violations, and disruptive events, 89.3 million people worldwide were forcibly displaced as of the end of 2021. Forcibly displaced people face a wide range of sexual and reproductive health challenges in their countries of origin, en route to final destinations, and on arrival in host communities. There is a growing urbanization of forcibly displaced persons, yet there is limited attention on sexual and reproductive health outcomes of this population. INCLUSION CRITERIA: This review will consider studies that include sexual and/or reproductive health outcomes and needs of forcibly displaced persons within urban environments in low- and middle-income countries. Published and unpublished evidence, including quantitative, qualitative, mixed methods research, and gray literature, will be eligible for inclusion. METHODS: MEDLINE, Embase, PsycINFO, CINAHL, IBSS, ASSIA, SSCI, and Global Medicus Index will be searched for English-language articles. Titles and abstracts will be screened against the inclusion criteria, followed by full-text review of potentially eligible studies, which will be independently assessed by 2 reviewers. Eligible articles will be extracted and charted. Results from extracted data will be tabulated and accompanied by a narrative summary to summarize and contextualize the extracted data to describe how the results relate to the review's objectives and question.

Differential secretion pathways of proteins fused to the Escherichia coli maltose binding protein (MBP) in Pichia pastoris.

The Escherichia coli maltose binding protein (MBP) is an N-terminal fusion partner that was shown to enhance the secretion of some heterologous proteins from the yeast Pichia pastoris, a popular host for recombinant protein expression. The amount of increase in secretion was dependent on the identity of the cargo protein, and the fusions were proteolyzed prior to secretion, limiting its use as a purification tag. In order to overcome these obstacles, we used the MBP as C-terminal partner for several cargo peptides. While the Cargo-MBP proteins were no longer proteolyzed in between these two moieties when the MBP was in this relative position, the secretion efficiency of several fusions was lower than when MBP was located at the opposite end of the cargo protein (MBP-Cargo). Furthermore, fluorescence analysis suggested that the MBP-EGFP and EGFP-MBP proteins followed different routes within the cell. The effect of several Pichia pastoris beta-galactosidase supersecretion (bgs) strains, mutants showing enhanced secretion of select reporters, was also investigated on both MBP-EGFP and EGFP-MBP. While the secretion efficiency, proteolysis and localization of the MBP-EGFP was influenced by the modified function of Bgs13, EGFP-MBP behavior was not affected in the bgs strain. Taken together, these results indicate that the location of the MBP in a fusion affects the pathway and trans-acting factors regulating secretion in P. pastoris.

Secretion and proteolysis of heterologous proteins fused to the Escherichia coli maltose binding protein in Pichia pastoris.

The Escherichia coli maltose binding protein (MBP) has been utilized as a translational fusion partner to improve the expression of foreign proteins made in E. coli. When located N-terminal to its cargo protein, MBP increases the solubility of intracellular proteins and improves the export of secreted proteins in bacterial systems. We initially explored whether MBP would have the same effect in the methylotrophic yeast Pichia pastoris, a popular eukaryotic host for heterologous protein expression. When MBP was fused as an N-terminal partner to several C-terminal cargo proteins expressed in this yeast, proteolysis occurred between the two peptides, and MBP reached the extracellular region unattached to its cargo. However, in two of three instances, the cargo protein reached the extracellular region as well, and its initial attachment to MBP enhanced its secretion from the cell. Extensive mutagenesis of the spacer region between MBP and its C-terminal cargo protein could not inhibit the cleavage although it did cause changes in the protease target sites in the fusion proteins, as determined by mass spectrometry. Taken together, these results suggested that an uncharacterized P. pastoris protease attacked at different locations in the region C-terminal of the MBP domain, including the spacer and cargo regions, but the MBP domain could still act to enhance the secretion of certain cargo proteins.