The extracellular matrix (ECM) is a mixture of glycoproteins and fibrous proteins that provide the biophysical properties necessary to maintain cellular homeostasis. ECM integrity is of particular importance during development, where it allows proper migration and cellular differentiation. Laminins are ECM heterotrimeric proteins consisting of α, β, and γ chains.
View Article and Find Full Text PDFELYS is a nucleoporin that localizes to the nuclear side of the nuclear pore complex (NPC) in interphase cells. In mitosis, it serves as an assembly platform that interacts with chromatin and then with nucleoporin subcomplexes to initiate post-mitotic NPC assembly. Here we identify ELYS as a major binding partner of the membrane protein VAPB during mitosis.
View Article and Find Full Text PDFThe technology of human pluripotent stem cell (hPSC)-based 3D organoid/assembloid cultures has become a powerful tool for the study of human embryonic development, disease modeling and drug discovery in recent years. The autonomic sympathetic nervous system innervates and regulates almost all organs in the body, including the heart. Yet, most reported organoids to date are not innervated, thus lacking proper neural regulation, and hindering reciprocal tissue maturation.
View Article and Find Full Text PDFSensory neurons (SNs) detect a wide range of information from the body and the environment that is critical for homeostasis. There are three main subtypes of SNs: nociceptors, mechanoreceptors, and proprioceptors, which express different membrane proteins, such as TRKA, TRKB, or TRKC, respectively. Human pluripotent stem cell technology provides an ideal platform to study development and diseases of SNs, however there is not a viable method to isolate individual SN subtype for downstream analysis available.
View Article and Find Full Text PDFMethods Enzymol
October 2022
Protein-protein interactions are central to most cellular processes and their dysregulation has been related to the development of various diseases. Proximity-based labeling methods are used to identify the endogenous interaction partners of specific proteins of interest (POIs). The POI is fused to promiscuous enzymes, which generate reactive species in vivo and label proteins in close vicinity.
View Article and Find Full Text PDFVAPB (Vesicle-Associated-membrane Protein-associated protein B) is a tail-anchored membrane protein of the endoplasmic reticulum that can also be detected at the inner nuclear membrane. As a component of many contact sites between the endoplasmic reticulum and other organelles, VAPB is engaged in multiple protein interactions with a plethora of binding partners. A mutant version of VAPB, P56S-VAPB, which results from a single point mutation, is involved in a familial form of amyotrophic lateral sclerosis (ALS8).
View Article and Find Full Text PDFMembrane contact sites (MCS) are sites of close apposition of two organelles that help in lipid transport and synthesis, calcium homeostasis and several other biological processes. The VAMP-associated proteins (VAPs) VAPA, VAPB, MOSPD2 and the recently described MOSPD1 and MOSPD3 are tether proteins of MCSs that are mainly found at the endoplasmic reticulum (ER). VAPs interact with various proteins with a motif called FFAT (two phenylalanines in an acidic tract), recruiting the associated organelle to the ER.
View Article and Find Full Text PDFEmerin is one of the best characterized proteins of the inner nuclear membrane, but can also occur at the level of the endoplasmic reticulum. We now use enhanced ascorbate peroxidase 2 (APEX2) to probe the environment of emerin. APEX2 can be used as a genetic tag that produces short-lived yet highly reactive biotin species, allowing the modification of proteins that interact with or are in very close proximity to the tagged protein.
View Article and Find Full Text PDFVesicle-associated membrane protein-associated protein B (VAPB) is a tail-anchored protein that is present at several contact sites of the endoplasmic reticulum (ER). We now show by immunoelectron microscopy that VAPB also localizes to the inner nuclear membrane (INM). Using a modified enhanced ascorbate peroxidase 2 (APEX2) approach with rapamycin-dependent targeting of the peroxidase to a protein of interest, we searched for proteins that are in close proximity to VAPB, particularly at the INM.
View Article and Find Full Text PDFEmbryonic stem cells have the ability to self-renew or differentiate and these processes are under tight control. We previously reported that the polyamine regulator AMD1 is critical for embryonic stem cell self-renewal. The polyamines putrescine, spermidine, and spermine are essential organic cations that play a role in a wide array of cellular processes.
View Article and Find Full Text PDFWe examined whether outcomes of care (amputation and hospitalisation) among patients with diabetes and foot ulcer differ between those who received pre-ulcer care from podiatrists and those who did not. Adult patients with diabetes and a diagnosis of a diabetic foot ulcer were found in the MarketScan Databases, 2005-2008. Multivariate Cox proportional hazard models estimated the hazard of amputation and hospitalisation.
View Article and Find Full Text PDFBackground: We sought to examine the economic value of specialized lower-extremity medical care by podiatric physicians in the treatment of diabetic foot ulcers by evaluating cost outcomes for patients with diabetic foot ulcer who did and did not receive care from a podiatric physician in the year before the onset of a foot ulcer.
Methods: We analyzed the economic value among commercially insured patients and Medicare-eligible patients with employer-sponsored supplemental medical benefits using the MarketScan Databases. The analysis consisted of two parts.
J Am Podiatr Med Assoc
November 2008
Background: An unanticipated decrease in applications to podiatric medical schools in the late 1990s has resulted in a decline in the number of podiatric physicians per capita in the United States. This study explores the implications of five possible scenarios for addressing this decline.
Methods: With the help of an advisory committee and data from the American Podiatric Medical Association, projections of the supply of podiatric physicians were developed using five different scenarios of the future.
Diabetes Forecast
September 2006