YBX1 Protein, Human (His)

YB1 is a DNA- and RNA-binding protein involved in various biological processes, including translational repression, RNA stabilization, mRNA splicing, DNA repair, and transcription regulation. It primarily functions as an RNA-binding protein, preferentially binding to the 5'-[CU]CUGCG-3' RNA motif and specifically recognizing mRNA transcripts modified by C5-methylcytosine (m5C). YB1 promotes mRNA stabilization by binding to m5C-containing mRNAs and recruiting the mRNA stability maintainer ELAVL1, thereby preventing mRNA decay. It is a component of the CRD-mediated complex that enhances MYC mRNA stability. Additionally, YB1 contributes to translation regulation by modulating interactions between mRNA and eukaryotic initiation factors (by similar). It plays a key role in defining the RNA composition of extracellular exosomes by sorting small non-coding RNAs (e.g., tRNAs, Y RNAs, Vault RNAs, and miRNAs) through recognition of m5C-containing RNAs. YB1 also acts as a key effector in epidermal progenitors, preventing senescence by regulating the translation of senescence-associated cytokine mRNAs. It is involved in pre-mRNA alternative splicing regulation by binding to splice sites. Furthermore, YB1 binds DNA, enhancing transcription of the multidrug resistance gene MDR1 in the presence of acetylated APEX1. It exhibits endonucleolytic activity, introducing nicks or breaks into double-stranded DNA, suggesting a role in DNA repair. The secreted form of YB1 functions as an extracellular mitogen, stimulating cell migration and proliferation.