NEUROLOGY
Gene
PADI4
Uniprot
Q9UM07
Protein
Protein-arginine deiminase type-4
See alternative names Protein-arginine deiminase type IV,
Peptidylarginine deiminase IV,
HL-60 PAD
Uniprot Function Description
Catalyzes the citrullination/deimination of arginine residues of proteins such as histones, thereby playing a key role in histone code and regulation of stem cell maintenance. Citrullinates histone H1 at 'Arg-54' (to form H1R54ci), histone H3 at 'Arg-2', 'Arg-8', 'Arg-17' and/or 'Arg-26' (to form H3R2ci, H3R8ci, H3R17ci, H3R26ci, respectively) and histone H4 at 'Arg-3' (to form H4R3ci). Acts as a key regulator of stem cell maintenance by mediating citrullination of histone H1: citrullination of 'Arg-54' of histone H1 (H1R54ci) results in H1 displacement from chromatin and global chromatin decondensation, thereby promoting pluripotency and stem cell maintenance. Promotes profound chromatin decondensation during the innate immune response to infection in neutrophils by mediating formation of H1R54ci. Citrullination of histone H3 prevents their methylation by CARM1 and HRMT1L2/PRMT1 and represses transcription. Citrullinates EP300/P300 at 'Arg-2142', which favors its interaction with NCOA2/GRIP1.
Sample type
Human EDTA plasma and serum are the recommended sample types. Human citrate plasma and heparin plasma are also accepted. For other samples types e.g cerebrospinal fluid, (CSF), tissue or cell lysates please we recommend Olink Target 96 panels. Please note that protein expression levels are expected to vary in different sample types and certain assays may be affected by interfering substances such as hemolysate.
Precision
Precision (repeatability) is calculated from linearized NPX values over LOD.
Dilution factor
For optimal assay readout, Olink Explore is run using different dilutions of the original samples (undiluted, 1:10, 1:100 or 1:1000). The dilution factor for this assay is noted below and should be taken into account when estimating the appropriate addressable biological concentration of the protein based on the in vitro validation data.
Sample distribution plot
The plot below shows the levels of protein measured in a number of commercial plasma samples. Healthy subjects are shown in blue and samples obtained from patients with a range of diseases are shown in red. The latter include inflammatory, cardiovascular, autoimmune & neurological diseases, as well as cancer. The data is shown to give a general idea of the sort of data range to expect, but cannot cover all potential levels that may be seen in clinical samples.
Biomarker Validation Data
Additional validation data, as well as a more detailed description of how the Olink panels are quality controlled can be found in our Data Validation documents – go to Document download center