Biomaterial Database

Phosphorylation of protein phosphatase-1 isoforms by cdc2-cyclin B in vitro. 1997

F Puntoni, and E Villa-Moruzzi

Department of Biomedicine, University of Pisa, Italy.

Protein Phosphatase-1 is phosphorylated in vitro by cdc2-cyclin B (Villa-Moruzzi, FEBS Lett 304: 211-215, 1992). In the present study we show that all the three Phosphatase-1 isoforms, alpha, gamma 1, delta, are phosphorylated by cdc2-cyclin B. Phosphorylation is specific for this kinase and involves a C-terminal Thr. This site is most likely Thr 320 in alpha (shown by others to be phosphorylated also by cdc2-cyclin A). Such Thr is conserved in gamma 1, delta and in the testis-specific gamma 2, and is the only Thr that fits the cdc2-consensus sequence in the C-terminal region. Phosphorylation of Phosphatase-1 purified from skeletal muscle, which is a mixture of the alpha, gamma 1 and delta isoforms, is up to 0.4 mol/mol and induces 30-35% enzyme inactivation. Following tryptic proteolysis each isoform yields a distinct phosphopeptide map. This is in agreement with the different sequences of the isoforms in the C-terminal regions and may be useful to distinguish the isoforms in extracts from metabolically-labelled cells. Our results suggest that all the Phosphatase-1 isoforms may be potentially regulated at M-phase.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D010748	Phosphopeptides	PEPTIDES that incorporate a phosphate group via PHOSPHORYLATION.	Phosphopeptide
D010749	Phosphoprotein Phosphatases	A group of enzymes removing the SERINE- or THREONINE-bound phosphate groups from a wide range of phosphoproteins, including a number of enzymes which have been phosphorylated under the action of a kinase. (Enzyme Nomenclature, 1992)	Phosphoprotein Phosphatase,Phosphoprotein Phosphohydrolase,Protein Phosphatase,Protein Phosphatases,Casein Phosphatase,Ecto-Phosphoprotein Phosphatase,Nuclear Protein Phosphatase,Phosphohistone Phosphatase,Phosphoprotein Phosphatase-2C,Phosphoseryl-Protein Phosphatase,Protein Phosphatase C,Protein Phosphatase C-I,Protein Phosphatase C-II,Protein Phosphatase H-II,Protein-Serine-Threonine Phosphatase,Protein-Threonine Phosphatase,Serine-Threonine Phosphatase,Threonine Phosphatase,Ecto Phosphoprotein Phosphatase,Phosphatase C, Protein,Phosphatase C-I, Protein,Phosphatase C-II, Protein,Phosphatase H-II, Protein,Phosphatase, Casein,Phosphatase, Ecto-Phosphoprotein,Phosphatase, Nuclear Protein,Phosphatase, Phosphohistone,Phosphatase, Phosphoprotein,Phosphatase, Phosphoseryl-Protein,Phosphatase, Protein,Phosphatase, Protein-Serine-Threonine,Phosphatase, Protein-Threonine,Phosphatase, Serine-Threonine,Phosphatase, Threonine,Phosphatase-2C, Phosphoprotein,Phosphatases, Phosphoprotein,Phosphatases, Protein,Phosphohydrolase, Phosphoprotein,Phosphoprotein Phosphatase 2C,Phosphoseryl Protein Phosphatase,Protein Phosphatase C I,Protein Phosphatase C II,Protein Phosphatase H II,Protein Phosphatase, Nuclear,Protein Serine Threonine Phosphatase,Protein Threonine Phosphatase,Serine Threonine Phosphatase
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D054645	Protein Phosphatase 1	A eukayrotic protein serine-threonine phosphatase subtype that dephosphorylates a wide variety of cellular proteins. The enzyme is comprised of a catalytic subunit and regulatory subunit. Several isoforms of the protein phosphatase catalytic subunit exist due to the presence of multiple genes and the alternative splicing of their mRNAs. A large number of proteins have been shown to act as regulatory subunits for this enzyme. Many of the regulatory subunits have additional cellular functions.	PP1c Enzyme,Phosphoprotein Phosphatase-1 delta,Phosphoprotein Phosphatase-1 gamma 1,Protein Phosphatase 1, Catalytic Subunit,Protein Phosphatase 1, Catalytic Subunit, alpha Isoform,Protein Phosphatase 1, Catalytic Subunit, beta Isoform,Protein Phosphatase 1, Catalytic Subunit, delta Isoform,Protein Phosphatase 1, Catalytic Subunit, gamma Isoform,Protein Phosphatase 1, Catalytic Subunit, gamma1 Isoform,Protein Phosphatase 1, Catalytic Subunit, gamma2 Isoform,Protein Phosphatase 1, Inhibitory Subunit,Protein Phosphatase 1, Regulatory Subunit,Protein Phosphatase 1C,Protein Phosphatase 1C gamma,Protein Phosphatase 1gamma,Protein Phosphatase-1,Protein Phosphatase-1 alpha,Protein Phosphatase-1 gamma 2,Protein Phosphatase-1G,Protein Serine-Threonine Phosphatase 1 beta,Protein-Serine-Threonine Phosphatase 1 beta,Type 1 Serine Threonine Protein Phosphatase,Phosphatase-1 delta, Phosphoprotein,Phosphoprotein Phosphatase 1 delta,Phosphoprotein Phosphatase 1 gamma 1,Protein Phosphatase 1 alpha,Protein Phosphatase 1 gamma 2,Protein Phosphatase 1G,Protein Serine Threonine Phosphatase 1 beta
D018844	Cyclin-Dependent Kinases	Protein kinases that control cell cycle progression in all eukaryotes and require physical association with CYCLINS to achieve full enzymatic activity. Cyclin-dependent kinases are regulated by phosphorylation and dephosphorylation events.	Cyclin-Dependent Kinase,Cyclin-Dependent Protein Kinase,cdk Proteins,Cyclin-Dependent Protein Kinases,Cyclin Dependent Kinase,Cyclin Dependent Kinases,Cyclin Dependent Protein Kinase,Cyclin Dependent Protein Kinases,Kinase, Cyclin-Dependent,Kinase, Cyclin-Dependent Protein,Protein Kinase, Cyclin-Dependent