通过SPA1对PIF4酸化的表征

Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...

Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...