Realistic enzymology for post-translational modification: Zero-order ultrasensitivity revisited
نویسندگان
چکیده
منابع مشابه
Realistic enzymology for post-translational modification: zero-order ultrasensitivity revisited.
Unlimited ultrasensitivity in a kinase/phosphatase "futile cycle" has been a paradigmatic example of collective behaviour in multi-enzyme systems. However, its analysis has relied on the Michaelis-Menten reaction mechanism, which remains widely used despite a century of new knowledge. Modifying and demodifying enzymes accomplish different biochemical tasks; the donor that contributes the modify...
متن کاملUltrasensitivity in biochemical systems controlled by covalent modification. Interplay between zero-order and multistep effects.
A previous analysis of covalent modification systems (Goldbeter, A., and Koshland, D. E., Jr. (1981) Proc. Natl. Acad. Sci. U. S. A. 78, 6840-6844) showed that steep transitions in the amount of modified protein can occur when the converter enzymes are saturated by their protein substrate. This "zero-order ultrasensitivity" can further be amplified when an effector acts at more than one step in...
متن کاملThreshold responses to morphogen gradients by zero-order ultrasensitivity
Translating a graded morphogen distribution into tight response borders is central to all developmental processes. Yet, the molecular mechanisms generating such behavior are poorly understood. During patterning of the Drosophila embryonic ventral ectoderm, a graded mitogen-activated protein kinase (MAPK) activation is converted into an all-or-none degradation switch of the Yan transcriptional r...
متن کاملZero-order ultrasensitivity in the regulation of glycogen phosphorylase.
The activity of glycogen phosphorylase (1,4-alpha-D-glucan:orthophosphate alpha-D-glucosyltransferase, EC 2.4.1.1) is controlled by a cyclic phosphorylation-dephosphorylation process through the action of the interconverting enzymes, phosphorylase b kinase (ATP:phosphorylase-b phosphotransferase, EC 2.7.1.38) and phosphorylase a phosphatase (phosphorylase a phosphohydrolase, EC 3.1.3.17). In mu...
متن کاملAllosteric post-translational modification codes.
Post-translational modifications (PTMs) have been recognized to impact protein function in two ways: (i) orthosterically, via direct recognition by protein domains or through interference with binding; and (ii) allosterically, via conformational changes induced at the functional sites. Because different chemical types of PTMs elicit different structural alterations, the effects of combinatorial...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Theoretical Biology
سال: 2012
ISSN: 0022-5193
DOI: 10.1016/j.jtbi.2012.07.012