Primary 24-hour cultures of hepatocytes on slides in a serum-free medium were studied. Circahoralian rhythm of protein synthesis served as a marker of cell cooperation. Stimulation of protein kinase activities by phorbol 12-myristate 13-acetate at 0.5 or 1.0 μM or forskolin at 10 μM led to visualization of the protein synthesis rhythm in sparse cultures, which were asynchronous in the control and with linear kinetics of protein synthesis. Inhibitors of protein kinase activities H7 (1-(5-isoquinolinylsulfonyl)-5-methylpiperasine dihydrochloride) at 40 μM or H8 (N-(2-[methylamino]ethyl)-5-isoquinolinesulfonamide hydrochloride) at 25 μM eliminated the protein synthesis rhythm in dense cultures, which are normally synchronous with oscillatory kinetics of protein synthesis. After inhibition of the protein kinase activities, gangliosides or phenylephrine did not synchronize the protein synthesis rhythm. Phorbol 12-myristate 13-acetate modulated the protein synthesis rhythm, shifted the rhythm phase, i.e., stimulation of the protein kinase activities, and, correspondingly, protein phosphorylation may be a factor of synchronization of synthesis oscillations in individual cells and of population rhythm formation. cAMP-dependent protein kinases also affect the protein synthesis rhythm. Thus, a cascade of processes leading to self-organization of hepatocytes during formation of summarized protein synthesis was revealed in a series of studies: signal of gangliosides or other calcium agonists → changes in the level of calcium ions in cytoplasm → increased protein kinase activities → protein phosphorylation → modulation of individual oscillations in the intensity of protein synthesis and their coordination in a summarized rhythm. Protein phosphorylation is a key process. The mechanisms of cell self-organization are similar in vitro and in vivo, specifically in the liver in situ.
Russian Journal of Developmental Biology – Springer Journals
Published: Sep 21, 2006
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera