Anti-Prolyl Endopeptidase/PREP Antibody Picoband®

Prolyl endopeptidase (PE) also known as prolyl oligopeptidase or post-proline cleaving enzyme is an enzyme that in humans is encoded by the PREP gene. The protein encoded by this gene is a cytosolic prolyl endopeptidase that cleaves peptide bonds on the C-terminal side of prolyl residues within peptides that are up to approximately 30 amino acids long. Prolyl endopeptidases have been reported to be involved in the maturation and degradation of peptide hormones and neuropeptides.

Receptor tyrosine-protein kinase erbB-4; Proto-oncogene-like protein c-ErbB-4; Tyrosine kinase-type cell surface receptor HER4; p180erbB4; ERBB4 intracellular domain; 4ICD; E4ICD; s80HER4; ERBB4; HER4

Expressed at highest levels in brain, heart, kidney, in addition to skeletal muscle, parathyroid, cerebellum, pituitary, spleen, testis and breast. Lower levels in thymus, lung, salivary gland, and pancreas. Isoform JM-A CYT-1 and isoform JM-B CYT-1 are expressed in cerebellum, but only the isoform JM-B is expressed in the heart.

Cancer, Cell Type Markers, Growth Factors, Growth Factors/Hormones, Oncoproteins, Oncoproteins/Suppressors, Protein Phosphorylation, Receptor Tyrosine Kinases, Signal Transduction, Tumor Associated, Tumor Biomarkers, Tyrosine Kinases

Tyrosine-protein kinase that plays an essential role as cell surface receptor for neuregulins and EGF family members and regulates development of the heart, the central nervous system and the mammary gland, gene transcription, cell proliferation, differentiation, migration and apoptosis. Required for normal cardiac muscle differentiation during embryonic development, and for postnatal cardiomyocyte proliferation. Required for normal development of the embryonic central nervous system, especially for normal neural crest cell migration and normal axon guidance. Required for mammary gland differentiation, induction of milk proteins and lactation. Acts as cell-surface receptor for the neuregulins NRG1, NRG2, NRG3 and NRG4 and the EGF family members BTC, EREG and HBEGF. Ligand binding triggers receptor dimerization and autophosphorylation at specific tyrosine residues that then serve as binding sites for scaffold proteins and effectors. Ligand specificity and signaling is modulated by alternative splicing, proteolytic processing, and by the formation of heterodimers with other ERBB family members, thereby creating multiple combinations of intracellular phosphotyrosines that trigger ligand- and context-specific cellular responses. Mediates phosphorylation of SHC1 and activation of the MAP kinases MAPK1/ERK2 and MAPK3/ERK1. Isoform JM-A CYT-1 and isoform JM-B CYT-1 phosphorylate PIK3R1, leading to the activation of phosphatidylinositol 3-kinase and AKT1 and protect cells against apoptosis. Isoform JM-A CYT-1 and isoform JM-B CYT-1 mediate reorganization of the actin cytoskeleton and promote cell migration in response to NRG1. Isoform JM-A CYT-2 and isoform JM-B CYT-2 lack the phosphotyrosine that mediates interaction with PIK3R1, and hence do not phosphorylate PIK3R1, do not protect cells against apoptosis, and do not promote reorganization of the actin cytoskeleton and cell migration. Proteolytic processing of isoform JM-A CYT-1 and isoform JM-A CYT-2 gives rise to the corresponding soluble intracellular domains (4ICD) that translocate to the nucleus, promote nuclear import of STAT5A, activation of STAT5A, mammary epithelium differentiation, cell proliferation and activation of gene expression. The ERBB4 soluble intracellular domains (4ICD) colocalize with STAT5A at the CSN2 promoter to regulate transcription of milk proteins during lactation. The ERBB4 soluble intracellular domains can also translocate to mitochondria and promote apoptosis.

1. Fulop, V., Bocskei, Z., Polgar, L. Prolyl oligopeptidase: an unusual beta-propeller domain regulates proteolysis. Cell 94: 161-170, 1998. 2. Goossens, F. J., Wauters, J. G., Vanhoof, G. C., Bossuyt, P. J., Schatteman, K. A., Loens, K., Scharpe, S. L. Subregional mapping of the human lymphocyte prolyl oligopeptidase gene (PREP) to human chromosome 6q22. Cytogenet. Cell Genet. 74: 99-101, 1996. 3. Valdivia, A., Irazusta, J., Fernandez, D., Mugica, J., Ochoa, C., Casis, L. Pyroglutamyl peptidase I and prolyl endopeptidase in human semen: increased activity in necrozoospermia. Regulatory Peptides 122: 79-84, 2004.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.