PI3K

By Yoskaly Lazo-Fernandez, PhD

Eukaryotic translation initiation factor 4E binding protein 1, or 4EBP1, is an mRNA translational repressor protein that negatively regulates eukaryotic translation initiation factor 4E, or EIF4E.  EIF4E is a protein that forms a complex necessary to block the 5’ ends of mRNA with a 7-methyl-guanosine five-prime cap structure, which is important for normal translation of mRNA.  Specifically, the EIF4E complex recruits 40s ribosome subunits to scan mRNA in order to regulate protein synthesis.  When EIF4E is bound to 4EBP1, it is held in an

CD19 is a cell surface protein member of the large immunoglobulin superfamily that complexes with CD21, CD81, and CD225 in the membrane of mature B-cells. A major function of CD19 is to assemble with the antigen receptor of B-lymphocytes to decrease the threshold for receptor-dependent stimulation, thus enhancing the specificity and sensitivity of B-cells towards antigens. CD19 plays a large role in regulating B-cell growth.

Akt1 is a serine/threonine-specific protein kinase involved in many cellular signaling pathways. The major function of this kinase is to mediate cell survival, but it also plays key roles in various other cellular functions such as glycogen synthesis and cell growth. Akt1 acts as a transducer for growth factor receptors that modulate phosphatidylinositol 3-kinase (PI3K) activity. Akt is believed to be a factor in cancer as the tumor suppressor phosphatase and tensin homolog (PTEN) was found to antagonize both PI-3 kinase and Akt kinase activity.

Phosphoserine, the phosphorylated modification of the amino acid serine, is a central post-translational modification within a cell for many biological and biomedical processes. The phosphorylation of specifically four residue types - histidine, serine, threonine, and tyrosine occurs both within the cell as well as at the cell surface. This exquisitely controlled regulatory system controls a vast number of intertwined and interconnected downstream signaling pathways and cascades.

The protein encoded by mTOR (mammalian target of rapamycin), also known as dTOR in Drosophila, belongs to a family of phosphatidylinositol kinase-related kinases. These kinases regulate fundamental processes of cell growth, proliferation, metabolism