hnRNPs H, H′ and F behave differently with respect to posttranslational cleavage and subcellular localization

AbstracthnRNPs H, H′ and F belong to a subfamily of the hnRNPs sharing a high degree of sequence identity. Eukaryotic expression and specific C-terminal antibodies were used to demonstrate great variation in the intracellular fate of the proteins. hnRNPs H and H′ become posttranslational cleaved into C-terminal 35 kDa proteins (HC, H′C) and possibly into N-terminal 22 kDa proteins. No detectable cleavage was observed for hnRNP F. hnRNP H/H′ is almost exclusively localized to the nucleus of many cell types while hnRNP F varies from a predominant nuclear localization in some cells to a predominant cytoplasmic localization in other cells. The different fates may reflect differences in functional roles that so far only have included nuclear functions. The presence of significant quantities of hnRNP F in the cytoplasm of many cells indicates that it also may have a functional role here

Proteomics and nucleotide profiling as tools for biomarker and drug target discovery

Proteomics has gone through tremendous development during recent decades [...

Artificial intelligence within ophthalmologic diseases

As ophthalmology is an increasingly busy medical specialty relying solidly on imaging technology, this review investigates the introduction of artificial intelligence to improve diagnostic performance and reduce human resources. In diabetic retinopathy screening, algorithms are now regulatory-approved for international markets but not yet tailored for the Danish system. In age-related macular degeneration, algorithms are now able to facilitate the classification and segmentation of disease activity, and in upcoming years, these are likely to assist us to improve diagnosis and provide subsequent clinical care

Risk of stroke, myocardial infarction, and death among patients with retinal artery occlusion and the effect of antithrombotic treatment

PURPOSE: To evaluate the risk of future stroke, myocardial infarction (MI), and death of patients with retinal artery occlusion (RAO) and the effect of various antithrombotic treatments as secondary prevention. METHODS: This cohort study was based on nationwide health registries and included the entire Danish population from 2000 to 2018. All patients with RAO were identified and their adjusted risks of stroke, MI, or death in time periods since RAO were compared with those of the Danish population. Furthermore, antithrombotic treatment of patients with RAO was determined by prescription claims, and the association with the risk of stroke, MI, or death was assessed using multivariate Poisson regression models and expressed as rate ratios (RR) with 95% confidence intervals (95% CIs). RESULTS: After inclusion, 6628 individuals experienced a first-time RAO, of whom 391 had a stroke, 66 had a MI, and 402 died within the first year after RAO. RAO was associated with an increased risk of stroke, MI, or death which persisted for more than 1 year for all three outcomes but was highest on days 3 to 14 after RAO for stroke, with an adjusted RR of 50.71 (95% CI, 41.55–61.87), and on days 14 to 90 after RAO for MI and death, with adjusted RRs of 1.98 (95% CI, 1.25–3.15) and 1.64 (95% CI, 1.28–189), respectively. Overall, antithrombotic treatment was not associated with any protective effect the first year. CONCLUSIONS: Patients with RAO had an increased risk of stroke, MI, or death. No protective effect of antithrombotic treatment was shown. TRANSLATIONAL RELEVANCE: These findings are relevant to the management of patients with RAO

Identification and characterization of endonuclein binding proteins: evidence of modulatory effects on signal transduction and chaperone activity

<p>Abstract</p> <p>Background</p> <p>We have previously identified endonuclein as a cell cycle regulated WD-repeat protein that is up-regulated in adenocarcinoma of the pancreas. Now, we aim to investigate its biomedical functions.</p> <p>Results</p> <p>Using the cDNA encoding human endonuclein, we have expressed and purified the recombinant protein from <it>Escherichia coli </it>using metal affinity chromatography. The recombinant protein was immobilized to a column and by affinity chromatography several interacting proteins were purified from several litres of placenta tissue extract. After chromatography the eluted proteins were further separated by two-dimensional gel electrophoresis and identified by tandem mass spectrometry. The interacting proteins were identified as; Tax interaction protein 1 (TIP-1), Aα fibrinogen transcription factor (P16/SSBP1), immunoglobulin heavy chain binding protein (BiP), human ER-associated DNAJ (HEDJ/DNAJB11), endonuclein interaction protein 8 (EIP-8), and pregnancy specific β-1 glycoproteins (PSGs). Surface plasmon resonance analysis and confocal fluorescence microscopy were used to further characterize the interactions.</p> <p>Conclusions</p> <p>Our results demonstrate that endonuclein interacts with several proteins indicating a broad function including signal transduction and chaperone activity.</p

Ca(2+ )binding to complement-type repeat domains 5 and 6 from the low-density lipoprotein receptor-related protein

BACKGROUND: The binding of ligands to clusters of complement-type repeat (CR)-domains in proteins of the low-density lipoprotein receptor (LDLR) family is dependent on Ca(2+ )ions. One reason for this cation requirement was identified from the crystal structure data for a CR-domain from the prototypic LDLR, which showed the burial of a Ca(2+ )ion as a necessity for correct folding and stabilization of this protein module. Additional Ca(2+ )binding data to other CR-domains from both LDLR and the LDLR-related protein (LRP) have suggested the presence of a conserved Ca(2+ )cage within CR-domains from this family of receptors that function in endocytosis and signalling. RESULTS: We have previously described the binding of several ligands to a fragment comprising the fifth and the sixth CR-domain (CR56) from LRP, as well as qualitatively described the binding of Ca(2+ )ions to this CR-domain pair. In the present study we have applied the rate dialysis method to measure the affinity for Ca(2+), and show that CR56 binds 2 Ca(2+ )ions with an average affinity of K(D )= 10.6 microM, and there is no indication of additional Ca(2+ )binding sites within this receptor fragment. CONCLUSIONS: Both CR-domains of CR56 bind a single Ca(2+ )ion with an affinity of 10.6 microM within the range of affinities demonstrated for several other CR-domains

Identification of differentially regulated proteins in a patient with Leber's Congenital Amaurosis – a proteomic study

BACKGROUND: To identify the pattern of protein expression in the retina from a patient with Leber's Congenital Amaurosis (LCA) secondary to a mutation in the AIPL1 gene. The retina from one eye of a patient with LCA and 7 control eyes were studied. The tissue was subjected to high resolution two-dimensional gel electrophoresis, image analysis and mass spectrometry, in an effort to identify differentially regulated proteins. RESULTS: In the LCA retina seven protein spots were differentially expressed. Six proteins were significantly up-regulated of which three could be identified as: αA-crystallin, triosephophate isomerase, and an N-terminal fragment of the β-chain of ATP synthase. One protein spot that was down-regulated in the LCA retina was identified as a C-terminal fragment of β-tubulin. CONCLUSION: Retinal tissue in LCA is characterised by an up-regulation of αA-crystallin, triosephosphate isomerase, and ATP synthase (β-chain fragment) and down-regulation of a fragment of β-tubulin. These proteins/protein fragments may play a crucial role for the retinal degeneration processes in LCA and other retinal dystrophies