Characterization and Intraorganellar Distribution of Protein Kinases in Amyloplasts Isolated from Cultured Cells of Sycamore (Acer pseudoplatanus L.).

Content Provider	Semantic Scholar
Author	Viale, Alejandro M. Ngernprasirtsiri, Jarunya Akazawa, Takashi
Copyright Year	1991
Abstract	Incubation of amyloplasts isolated from cultured cells of sycamore (Acer pseudoplatanus L.) with [gamma-(32)P]ATP resulted in the rapid phosphorylation (half-time of 40 seconds at 25 degrees Celcius) of organellar polypeptides. The preferred substrate for amyloplast protein kinases was Mg(2+). ATP, and recovery of only [(32)P]serine after partial acid hydrolysis indicated the predominance of protein serine kinases in the organelle. These activities were located in the envelope and stromal fractions of the plastid, which showed different specificities toward exogenous protein substrates and distinct patterns of phosphorylation of endogenous polypeptides. A 66-kilodalton polypeptide, inaccessible to an exogenously added protease, was one of the major phosphorylated products found in intact amyloplasts at low [gamma-(32)P] adenosine triphosphate concentrations. This polypeptide represented the major phosphoprotein observed with the isolated envelope fraction. The patterns of polypeptide phosphorylation found in intact amyloplasts and chloroplasts from cultured cell lines of sycamore were clearly distinguishable. The overall results indicate the presence of protein phosphorylation systems unique to this reserve plastid present in nonphotosynthetic tissues.
File Format	PDF HTM / HTML
DOI	10.1104/pp.96.4.1142
PubMed reference number	16668311
Journal	Medline
Volume Number	96
Issue Number	4
Alternate Webpage(s)	http://www.plantphysiol.org/content/plantphysiol/96/4/1142.full.pdf
Alternate Webpage(s)	https://doi.org/10.1104/pp.96.4.1142
Journal	Plant physiology
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article