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1.
Econ Lett ; 219: 110792, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35990574

ABSTRACT

This study extends the earlier literature on changes in school enrollment in the wake of the COVID-19 pandemic by using data for the second COVID-19 school year (2021-2022) from the state of New York. Contrary to expectations that the resumption of fully-live instruction would reverse the first COVID-19 year's declines in public school enrollment, we find that enrollment continued to drop sharply in the second COVID-19 school year, when schools were entirely back to in-person learning. These declines in enrollment vary substantially by grade, race and poverty and are robust to controlling for other COVID-19 related factors. In addition, we find mixed results for the number of private school students but significant increases in home-schooled students in the two COVID-19 years. The findings have important educational and fiscal implications.

2.
Biochim Biophys Acta Rev Cancer ; 1877(1): 188668, 2022 01.
Article in English | MEDLINE | ID: mdl-34896436

ABSTRACT

Tamoxifen is a commonly used drug in the treatment of ER + ve breast cancers since 1970. However, development of resistance towards tamoxifen limits its remarkable clinical success. In this review, we have attempted to provide a brief overview of multiple mechanism that may lead to tamoxifen resistance, with a special emphasis on the roles played by the oncogenic kinase- PAK1. Analysing the genomic data sets available in the cBioPortal, we found that PAK1 gene amplification significantly affects the Relapse Free Survival of the ER + ve breast cancer patients. While PAK1 is known to promote tamoxifen resistance by phosphorylating ERα at Ser305, existing literature suggests that PAK1 can fuel up tamoxifen resistance obliquely by phosphorylating other substrates. We have summarised some of the approaches in the mass spectrometry based proteomics, which would enable us to study the tamoxifen resistance specific phosphoproteomic landscape of PAK1. We also propose that elucidating the multiple mechanisms by which PAK1 promotes tamoxifen resistance might help us discover druggable targets and biomarkers.


Subject(s)
Breast Neoplasms , Tamoxifen , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Drug Resistance, Neoplasm/genetics , Female , Humans , Tamoxifen/pharmacology , Tamoxifen/therapeutic use , p21-Activated Kinases/genetics
3.
Elife ; 82019 09 25.
Article in English | MEDLINE | ID: mdl-31552827

ABSTRACT

Hsf1 is an ancient transcription factor that responds to protein folding stress by inducing the heat-shock response (HSR) that restore perturbed proteostasis. Hsp70 chaperones negatively regulate the activity of Hsf1 via stress-responsive mechanisms that are poorly understood. Here, we have reconstituted budding yeast Hsf1-Hsp70 activation complexes and find that surplus Hsp70 inhibits Hsf1 DNA-binding activity. Hsp70 binds Hsf1 via its canonical substrate binding domain and Hsp70 regulates Hsf1 DNA-binding activity. During heat shock, Hsp70 is out-titrated by misfolded proteins derived from ongoing translation in the cytosol. Pushing the boundaries of the regulatory system unveils a genetic hyperstress program that is triggered by proteostasis collapse and involves an enlarged Hsf1 regulon. The findings demonstrate how an apparently simple chaperone-titration mechanism produces diversified transcriptional output in response to distinct stress loads.


Subject(s)
DNA-Binding Proteins/biosynthesis , Gene Expression Regulation, Fungal , HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Proteins/biosynthesis , Saccharomyces cerevisiae Proteins/biosynthesis , Saccharomyces cerevisiae/metabolism , Transcription Factors/biosynthesis , DNA, Fungal/metabolism , Hot Temperature , Protein Binding , Protein Folding , Saccharomyces cerevisiae/radiation effects
4.
Asian J Transfus Sci ; 13(1): 57-59, 2019.
Article in English | MEDLINE | ID: mdl-31360013

ABSTRACT

Platelet (PLT) transfusion is undertaken in a variety of clinical settings with thrombocytopenia, with or without bleeding. Since PLTs are most often stored in donor plasma, group-specific PLT transfusions are preferred to out-of-group transfusions. PLTs adsorb ABO antigens over their surface from the plasma. In major ABO-incompatible PLT transfusions, anti-A/B from the patient plasma react with the ABO antigens on transfused PLTs and can potentially cause adverse reactions or PLT refractoriness. Transfusion of PLTs with major ABO incompatibility, though effective in preventing clinical bleeding, is associated with reduced posttransfusion PLT count increments. In minor incompatible PLT transfusion transfused, anti-A/B can cause hemolytic transfusion reaction (HTR) which is not always related to a high titer of anti-A/B in the donor. Although attempts are made to practice ABO identical PLT transfusion, most centers practice out-of-group random donor platelets (RDPs) as well as single-donorplatelets (SDP) transfusion. The limited PLT shelf life does not always permit ABO identical PLT transfusion. At our center, ABO-specific PLT transfusions are practiced where possible, and in case of minor ABO-incompatible transfusions, antibody titers are not done. Here, we report a case of HTR due to out-of-group SDP transfusion, detected in the laboratory after an incompatible red blood cell (RBC) crossmatch.

6.
J Biol Chem ; 291(47): 24579-24593, 2016 Nov 18.
Article in English | MEDLINE | ID: mdl-27703006

ABSTRACT

CRAF kinase maintains cell viability, growth, and proliferation by participating in the MAPK pathway. Unlike BRAF, CRAF requires continuous chaperoning by Hsp90 to retain MAPK signaling. However, the reason behind the continuous association of Hsp90 with CRAF is still elusive. In this study, we have identified the bipartite role of Hsp90 in chaperoning CRAF kinase. Hsp90 facilitates Ser-621 phosphorylation of CRAF and prevents the kinase from degradation. Co-chaperone Cdc37 assists in this phosphorylation event. However, after folding, the stability of the kinase becomes insensitive to Hsp90 inhibition, although the physical association between Hsp90 and CRAF remains intact. We observed that overexpression of Hsp90 stimulates MAPK signaling by activating CRAF. The interaction between Hsp90 and CRAF is substantially increased under an elevated level of cellular Hsp90 and in the presence of either active Ras (RasV12) or EGF. Surprisingly, enhanced binding of Hsp90 to CRAF occurs prior to the Ras-CRAF association and facilitates actin recruitment to CRAF for efficient Ras-CRAF interaction, which is independent of the ATPase activity of Hsp90. However, monomeric CRAF (CRAFR401H) shows abrogated interaction with both Hsp90 and actin, thereby affecting Hsp90-dependent CRAF activation. This finding suggests that stringent assemblage of Hsp90 keeps CRAF kinase equipped for participating in the MAPK pathway. Thus, the role of Hsp90 in CRAF maturation and activation acts as a limiting factor to maintain the function of a strong client like CRAF kinase.


Subject(s)
HSP90 Heat-Shock Proteins/metabolism , MAP Kinase Signaling System/physiology , Proto-Oncogene Proteins c-raf/metabolism , Amino Acid Substitution , Enzyme Activation/physiology , HEK293 Cells , HSP90 Heat-Shock Proteins/genetics , Humans , Mutation, Missense , Oncogene Protein p21(ras)/genetics , Oncogene Protein p21(ras)/metabolism , Phosphorylation/physiology , Proto-Oncogene Proteins c-raf/genetics
7.
Mol Biol Cell ; 26(9): 1583-600, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25739454

ABSTRACT

Hsp70 aids in protein folding and directs misfolded proteins to the cellular degradation machinery. We describe discrete roles of Hsp70,SSA1 as an important quality-control machinery that switches functions to ameliorate the cellular environment. SSA1 facilitates folding/maturation of newly synthesized protein kinases by aiding their phosphorylation process and also stimulates ubiquitylation and degradation of kinases in regular protein turnover or during stress when kinases are denatured or improperly folded. Significantly, while kinases accumulate as insoluble inclusions upon SSA1 inhibition, they form soluble inclusions upon Hsp90 inhibition or stress foci during heat stress. This suggests formation of inclusion-specific quality-control compartments under various stress conditions. Up-regulation of SSA1 results in complete removal of these inclusions by the proteasome. Elevation of the cellular SSA1 level accelerates kinase turnover and protects cells from proteotoxic stress. Upon overexpression, SSA1 targets heat-denatured kinases toward degradation, which could enable them to recover their functional state under physiological conditions. Thus active participation of SSA1 in the degradation of misfolded proteins establishes an essential role of Hsp70 in deciding client fate during stress.


Subject(s)
Adenosine Triphosphatases/physiology , Cyclic AMP-Dependent Protein Kinases/metabolism , HSP70 Heat-Shock Proteins/physiology , MAP Kinase Kinase Kinases/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae Proteins/physiology , Saccharomyces cerevisiae/enzymology , Phosphorylation , Protein Folding , Proteolysis , Ubiquitination
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