Two Undervalued Functions of the Golgi Apparatus: Removal of Excess Ca2+ and Biosynthesis of Farnesol-Like Sesquiterpenoids, Possibly as Ca2+-Pump Agonists and Membrane "Fluidizers-Plasticizers".

摘要: The extensive literature dealing with the Golgi system emphasizes its role in protein secretion and modification, usually without specifying from which evolutionary ancient cell physiological necessity such originated. Neither does it specify functional requirements secreted proteins must meet. From a reinterpretation of some classical recent data gained mainly, but not exclusively, (insect) endocrinology, view emerged that likely primordial function rough endoplasmic reticulum (RER)-Golgi complex all eukaryotes was any type removal toxic excess Ca2+ cytoplasm. Such activity requires concurrent large amounts Ca2+-carrying/transporting acting as micro-conveyor belt inside RER-Golgi. Thus, (fitness increasing) is subordinate to removal. Milk high content (60-90 mM vs. 100 nM unstimulated mammary gland cells) an extreme example. sarco(endo)plasmatic Ca2+-ATPases (SERCAs) SPCA1a Ca2+/Mn2+ transport ATPases are major players through Golgi. Both blocked by sesquiterpenoid thapsigargin. This strengthens hypothesis (2014) endogenous farnesol-like sesquiterpenoids (FLSs) may act long sought for still unidentified agonist(s) Ca2+-pumps both ER A second putative also emerges. fusion incoming outgoing vesicles, respectively, at cis- trans- side stacks, membrane requiring flexibility fast self-closing involved membranes. These properties may-possibly partially-be controlled hydrophobic "fluidizers" FLSs prime candidates. reexamination unexplained suggests they synthesized itself. game-changing endorsed several arguments data, date 1964, insect corpus allatum (CA), production site farnesol-esters, has active systems. addition secreting FLS, particular juvenile hormone(s), secretes protein(s) or peptide(s) thus far unknown function. paper answers various open questions physiology general endocrinology.