Characterization of phosphotyrosyl-protein phosphatase activity associated with calcineurin

Jonathan Chernoff; Mary Ann Sells; Heng Chun Li

doi:10.1016/0006-291X(84)90698-3

Characterization of phosphotyrosyl-protein phosphatase activity associated with calcineurin

Jonathan Chernoff, Mary Ann Sells, Heng Chun Li

Cancer Signaling and Microenvironment (CSM)

City University of New York

Research output: Contribution to journal › Article › peer-review

39 Scopus citations

Abstract

Calcineurin purified from bovine brain is shown to possess phosphotyrosyl-protein phosphatase activity towards proteins phosphorylated by the epidermal growth factor receptor/kinase. The phosphatase activity is augmented by Ca²⁺/calmodulin or divalent cation (Ni²⁺ > Mn²⁺ > Mg²⁺ > Co²⁺). In the simultaneous presence of all three effectors the enzymatic activity is synergistically increased. Ca²⁺/calmodulin activates the Mg²⁺-supported activity by decreasing the K_m value for phosphotyrosyl-casein from 2.2 to 0.6 μM, and increasing the V_max from 0.4 to 4.6 nmol/min/mg. These results represent the first demonstration that calcineurin can dephosphorylate phosphotyrosyl-proteins and suggest a novel mechanism of activation of this enzyme.

Original language	English
Pages (from-to)	141-148
Number of pages	8
Journal	Biochemical and Biophysical Research Communications
Volume	121
Issue number	1
DOIs	https://doi.org/10.1016/0006-291X(84)90698-3
State	Published - May 31 1984

Access to Document

10.1016/0006-291X(84)90698-3

Cite this

@article{1583f308019c4f5fb76f6b4e40f549ea,

title = "Characterization of phosphotyrosyl-protein phosphatase activity associated with calcineurin",

abstract = "Calcineurin purified from bovine brain is shown to possess phosphotyrosyl-protein phosphatase activity towards proteins phosphorylated by the epidermal growth factor receptor/kinase. The phosphatase activity is augmented by Ca2+/calmodulin or divalent cation (Ni2+ > Mn2+ > Mg2+ > Co2+). In the simultaneous presence of all three effectors the enzymatic activity is synergistically increased. Ca2+/calmodulin activates the Mg2+-supported activity by decreasing the Km value for phosphotyrosyl-casein from 2.2 to 0.6 μM, and increasing the Vmax from 0.4 to 4.6 nmol/min/mg. These results represent the first demonstration that calcineurin can dephosphorylate phosphotyrosyl-proteins and suggest a novel mechanism of activation of this enzyme.",

author = "Jonathan Chernoff and Sells, {Mary Ann} and Li, {Heng Chun}",

year = "1984",

month = may,

day = "31",

doi = "10.1016/0006-291X(84)90698-3",

language = "English",

volume = "121",

pages = "141--148",

journal = "Biochemical and Biophysical Research Communications",

issn = "0006-291X",

publisher = "Academic Press Inc.",

number = "1",

}

TY - JOUR

T1 - Characterization of phosphotyrosyl-protein phosphatase activity associated with calcineurin

AU - Chernoff, Jonathan

AU - Sells, Mary Ann

AU - Li, Heng Chun

PY - 1984/5/31

Y1 - 1984/5/31

N2 - Calcineurin purified from bovine brain is shown to possess phosphotyrosyl-protein phosphatase activity towards proteins phosphorylated by the epidermal growth factor receptor/kinase. The phosphatase activity is augmented by Ca2+/calmodulin or divalent cation (Ni2+ > Mn2+ > Mg2+ > Co2+). In the simultaneous presence of all three effectors the enzymatic activity is synergistically increased. Ca2+/calmodulin activates the Mg2+-supported activity by decreasing the Km value for phosphotyrosyl-casein from 2.2 to 0.6 μM, and increasing the Vmax from 0.4 to 4.6 nmol/min/mg. These results represent the first demonstration that calcineurin can dephosphorylate phosphotyrosyl-proteins and suggest a novel mechanism of activation of this enzyme.

AB - Calcineurin purified from bovine brain is shown to possess phosphotyrosyl-protein phosphatase activity towards proteins phosphorylated by the epidermal growth factor receptor/kinase. The phosphatase activity is augmented by Ca2+/calmodulin or divalent cation (Ni2+ > Mn2+ > Mg2+ > Co2+). In the simultaneous presence of all three effectors the enzymatic activity is synergistically increased. Ca2+/calmodulin activates the Mg2+-supported activity by decreasing the Km value for phosphotyrosyl-casein from 2.2 to 0.6 μM, and increasing the Vmax from 0.4 to 4.6 nmol/min/mg. These results represent the first demonstration that calcineurin can dephosphorylate phosphotyrosyl-proteins and suggest a novel mechanism of activation of this enzyme.

UR - http://www.scopus.com/inward/record.url?scp=0021253895&partnerID=8YFLogxK

U2 - 10.1016/0006-291X(84)90698-3

DO - 10.1016/0006-291X(84)90698-3

M3 - Article

SN - 0006-291X

VL - 121

SP - 141

EP - 148

JO - Biochemical and Biophysical Research Communications

JF - Biochemical and Biophysical Research Communications

IS - 1

ER -

Characterization of phosphotyrosyl-protein phosphatase activity associated with calcineurin

Abstract

Access to Document

Other files and links

Fingerprint

Cite this