Loading AI tools
Protein-coding gene in the species Homo sapiens From Wikipedia, the free encyclopedia
Phosphatidylinositol 4-kinase beta is an enzyme that in humans is encoded by the PI4KB gene.[5][6][7]
PI4KB | |||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||||||||||||||||||||
Identifiers | |||||||||||||||||||||||||||||||
Aliases | PI4KB, NPIK, PI4K-BETA, PI4K92, PI4KBETA, PI4KIIIBETA, PIK4CB, phosphatidylinositol 4-kinase beta, PI4KIII | ||||||||||||||||||||||||||||||
External IDs | OMIM: 602758; MGI: 1334433; HomoloGene: 6741; GeneCards: PI4KB; OMA:PI4KB - orthologs | ||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||
Wikidata | |||||||||||||||||||||||||||||||
|
This gene encodes a phosphatidylinositol 4-kinase which catalyzes phosphorylation of phosphatidylinositol at the D-4 position, yielding phosphatidylinositol 4-phosphate (PI4P). Besides the fact, that PI4P serves as a precursor for other important phosphoinositides, such as phosphatidylinositol 4,5-bisphosphate, PI4P is an essential molecule in the cellular signaling and trafficking especially in the Golgi apparatus and the trans Golgi network.
Phosphatidylinositol 4-kinases are evolutionary conserved among eukaryotes and include four human isoforms
Phosphatidylinositol 4-kinase beta (PI4KB) is a soluble protein shuttling between the cytoplasm and the nucleus,[8] and can be recruited to the membranes of the Golgi system via protein-protein interactions, e.g. with small GTP binding proteins Arf1[9] and Rab11,[10] or a Golgi adaptor protein ACBD3.[11][12] PI4KB can be phosphorylated by the protein kinase D,[13] which promotes the interaction with 14-3-3 proteins and stabilization of the protein in its active conformation.[14] In cytoplasm PI4KB regulates the trafficking from the Golgi system to the plasma membrane, nevertheless, its nuclear function remains to be determined.
A wide range of positive-sense single-stranded RNA viruses (e.g. picornaviruses) including many important human pathogens hijack human PI4KB kinase to generate specific PI4P-enriched organelles called membranous webs.[15] These organelles are then used as specific platforms for the effective viral replication within the host cell.
Furthermore, PI4KB homologue from the protozoan parasite Plasmodium falciparum has been identified as a target of imidopyrazines, an antimalarial compound class.[16]
PI4KB is composed of a proline-rich N-terminal region, a central helical domain, and a kinase domain located C-terminally. The N-terminal region contains a physiologically important binding site for a Golgi adaptor protein ACBD3, but is likely disordered and dispensable for the kinase activity. The central helical domain is responsible for the interaction with a small guanosine triphosphatase Rab11. The kinase domain can be divided into N-terminal and C-terminal lobes with the ATP binding groove and putative phosphatidylinositol binding pocket in a cleft between the lobes.[17] In addition, an ALPS motif has been identified in the extreme C-terminal region of PI4KB, which favors its association with unsaturated or loosely packed membranes regions.[18]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.