NCBI Summary:
This gene uses alternative splicing to generate two different proteins- high molecular weight kininogen (HMWK) and low molecular weight kininogen (LMWK). HMWK is essential for blood coagulation and assembly of the kallikrein-kinin system. Also, bradykinin, a peptide causing numerous physiological effects, is released from HMWK. Bradykinin also functions as an antimicrobial peptide with antibacterial and antifungal activity. In contrast to HMWK, LMWK is not involved in blood coagulation. Three transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Nov 2014]
General function
Ligand, Extracellular binding protein
Comment
Cellular localization
Secreted
Comment
Ovarian function
Comment
Novel Serum Biomarkers Detected by Protein Array in Polycystic Ovary Syndrome with Low Progesterone Level. Zheng Q et al. (2018) Polycystic ovary syndrome (PCOS), characterized by female infertility and metabolic abnormalities, is one of the most common endocrine disorders. The etiology of PCOS remains unknown. The comprehensive analysis of protein alterations in PCOS patients is meaningful for identifying diagnostic biomarkers of PCOS. Here, we explored the clinical value of serum proteins as novel biomarkers to detect PCOS with low progesterone level. A total of 43 patients with PCOS and 30 healthy women were enrolled. Protein array was used to detect the variations of serum proteins between PCOS patients and healthy women. The level of five serum proteins was further confirmed by ELISA and western blot. The human ovarian granulosa cells (KGN) was cultured to examine the underlying mechanism of PCOS. CCK8 assay and western blot were carried out to evaluate the alterations in proliferative ability, TUNEL assay and DAPI staining to detect the apoptosis of KGN cells. Among the 507 proteins, we identified 76 differentially expressed serum proteins (≧1.5 fold), with 40 elevated and 36 decreased proteins. Moreover, 47 proteins were newly reported in PCOS. The alterations in the five significantly decreased proteins (EREG, inhibin βA, IDE, PDGF-D and KNG1) were further confirmed by ELISA and western blot. The level of these proteins were directly associated with the low progesterone, and the expression could be upregulated by progesterone. EREG and inhibin βA also promoted the proliferation and inhibited the apoptosis of ovarian granulosa cells. The study highlights that serum proteins are differentially expressed in PCOS patients and healthy women, and EREG and inhibin βA levels are upregulated by progesterone, which are correlated with ovarian functions. The study suggests that EREG and inhibin βA may be applied as novel potential biomarkers for PCOS with low progesterone level.//////////////////
Expression regulated by
Comment
Ovarian localization
, Follicular Fluid
Comment
Apolipoprotein A-IV as a novel gene associated with polycystic ovary syndrome. Kim YS et al. Polycystic ovary syndrome (PCOS) is a common endocrine-metabolic disorder, affecting 6-10% of women of reproductive age. The etiology remains poorly understood. To investigate the differentially expressed proteins from PCOS patients versus healthy women, the protein expression in follicular fluid was analyzed using two-dimensional electrophoresis (2-DE). Since follicular fluid contains a number of secretory proteins required for oocyte fertilization and follicle maturation, it is possible that follicular fluid can be used as a provisional source for identifying pivotal proteins associated with PCOS. In this study, six overexpressed proteins [kininogen1, cytokeratin9, antithrombin, fibrinogen ?-chain, apolipoproteinA-IV (apoA-IV) precursor and a-1-B-glycoprotein (A1BG)] in follicular fluids from PCOS patients were identified with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) and nano LC-MS/MS. Western blot analysis confirmed that the protein expression levels of apoA-IV precursor and A1BG were increased in follicular fluid from PCOS patients compared with those from normal controls. The analysis of protein expression for other proteins revealed individual variation. These results facilitate the understanding of the molecular mechanisms of PCOS and provide candidate biomarkers for the development of diagnostic and therapeutic tools.