HNRNPK : heterogeneous nuclear ribonucleoprotein K
Description
The HNRNPK (heterogeneous nuclear ribonucleoprotein K) is a protein-coding gene located on chromosome 9.
The HNRNPK gene provides instructions for making a protein called heterogenous nuclear ribonucleoprotein K (hnRNP K). This protein attaches (binds) to DNA or its chemical cousin RNA and to other proteins. It acts as a docking site to bring together different molecules in the cell, which is important for relaying signals and controlling cellular functions. By bringing certain proteins together with DNA or RNA, the hnRNP K protein helps control the activity of genes and the production of proteins. By regulating gene activity and protein production, hnRNP K is involved in many cellular processes, including growth and division (proliferation) of cells, maturation of cells to take on specialized function (differentiation), and self-destruction (apoptosis) of cells when they are no longer needed.The hnRNP K protein plays a role in the normal development or function of many body systems. In the brain, the protein may be involved in a process called synaptic plasticity, which is the ability of the connections between neurons (synapses) to change and adapt over time in response to experience. This process is critical for learning and memory. Another process in the brain involving the hnRNP K protein is the growth of nerve cell extensions called axons, which are essential for transmission of nerve impulses. While the protein is likely critical in other systems and processes, its role is not well understood.
HNRNPK is a major pre-mRNA binding protein that binds strongly to poly(C) sequences, suggesting a role in nuclear metabolism of hnRNAs, particularly those rich in cytidine. It also binds to poly(C) single-stranded DNA. HNRNPK plays a crucial role in the p53/TP53 response to DNA damage, acting at both transcription activation and repression levels. When modified by SUMOylation, it acts as a transcriptional coactivator of p53/TP53, influencing the induction of p21/CDKN1A and 14-3-3 sigma/SFN. In terms of repression, HNRNPK interacts with long intergenic RNA p21 (lincRNA-p21), a non-coding RNA induced by p53/TP53, which is necessary for apoptosis induction but not cell cycle arrest. HNRNPK is part of a ribonucleoprotein complex containing ZNF827, HNRNPL, and the circular RNA circZNF827, potentially negatively regulating the transcription of neuronal differentiation genes. It has been identified in the spliceosome C complex and is part of a transcription inhibitory ribonucleoprotein complex composed of circZNF827, ZNF827, and HNRNPL. HNRNPK interacts with RBM42, ZIK1, BRDT, ANKRD28, ASFV p30 protein, DDX1, MDM2, p53/TP53, IVNS1ABP, PPIA/CYPA, and HCV core protein.
HNRNPK is also known as AUKS, CSBP, HNRPK, TUNP.
Associated Diseases
- Neurodevelopmental disorder-craniofacial dysmorphism-cardiac defect-skeletal anomalies syndrome due to 9q21.3 microdeletion
- Au-Kline syndrome
- Neurodevelopmental disorder-craniofacial dysmorphism-cardiac defect-skeletal anomalies syndrome due to a point mutation
