Translation Factors

4E-BP1 (Eukaryotic translation Initiation Factor 4E Binding Protein 1) is a 118-amino acid protein (~13kDa). Binding of eIF4EBP1 to eIF4E is reversible and is dependent on the phosphorylation status of eIF4EBP1. Non phosphorylated eIF4EBP1 will bind strongly to eIF4E while the phosphorylated form will not. Akt, TOR, MAP kinase, S6 kinase and Cdc2 are known kinases capable of inactivating eIF4EBP1 binding to eIF4E by phosphorylating either threonines 35, 45, 69 or serine 64. Although, not all phosphorylation events equally block the eIF4EBP1-eIF4E interaction.

4E-BP1 (Eukaryotic translation Initiation Factor 4E Binding Protein 1) is a 118-amino acid protein (~13kDa). Binding of eIF4EBP1 to eIF4E is reversible and is dependent on the phosphorylation status of eIF4EBP1. Non phosphorylated eIF4EBP1 will bind strongly to eIF4E while the phosphorylated form will not. Akt, TOR, MAP kinase, S6 kinase and Cdc2 are known kinases capable of inactivating eIF4EBP1 binding to eIF4E by phosphorylating either threonines 35, 45, 69 or serine 64. Although, not all phosphorylation events equally block the eIF4EBP1-eIF4E interaction.

Component of gems 2 (gemin-2) plays an essential role in spliceosomal snRNP assembly in the cytoplasm and is required for pre-mRNA splicing in the nucleus. Gemin-2 is localized in subnuclear structures next to coiled bodies, called gems, which are highly enriched in spliceosomal snRNPs. Gemin-2 is also found in the cytoplasm.

The 60 kDa SS-A/Ro ribonucleoprotein (SSA) is an RNA-binding protein that binds to several small cytoplasmic RNA molecules known as Y RNAs. SSA may protect these RNAs from degradation. SSA is phosphorylated by ATM or ATR upon DNA damage. Sera from patients with systemic lupus erythematosus (SLE) often contain antibodies that react with normal cellular SSA2.

Adipocyte enhancer-binding protein 1 (AEBP1) up-regulates MAP-kinase activity leading to enhanced proliferation and reduced differentiation of the adipocyte. AEBP1 also up-regulates NF-kappa-B activity in macrophages via phosphorylation and subsequent degradation of I-kappa-B-alpha. This leads to enhanced macrophage inflammatory responsiveness. It can also act as a transcriptional repressor.