TY - JOUR
T1 - Role of the kinase activation loop on protein kinase C θ activity and intracellular localisation
AU - Sparatore, Bianca
AU - Passalacqua, Mario
AU - Pedrazzi, Marco
AU - Ledda, Sabina
AU - Patrone, Mauro
AU - Gaggero, Deborah
AU - Pontremoli, Sandro
AU - Melloni, Edon
N1 - Funding Information:
This work was supported by grants from the Italian Ministero dell’Istruzione, Università e Ricerca (Cofin 2002), from the University of Genoa and FIRB, Post Genome, Subproject 1. We thank Dr S. Shaw and Dr Y. Liu at the National Cancer Institute, Bethesda, MD, USA for providing pSer 676 and pSer 695 PKCθ antibodies.
PY - 2003/11/6
Y1 - 2003/11/6
N2 - Multiple protein kinase C (PKC) θ species, identified in an erythroleukaemia cell line, have been characterised in terms of their molecular properties and intracellular distribution. PKCθs localised in the detergent-soluble cell fraction have an Mr of 76 kDa (θ-76) and contain Thr538 or pThr538 in the kinase activation loop. In contrast, PKCθs localised in the Golgi complex have an M r of 85 kDa (θ-85) and, although unphosphorylated at Thr 538, are catalytically active. Strikingly, only θ-76 species which are unphosphorylated at Thr538 can undergo autocatalytic conversion to θ-85. Moreover, a Thr538→Ala PKCθ mutant is constitutively localised in the Golgi complex, confirming that changes in the phosphorylation state of this residue play a pivotal role in the overall control of catalytic properties and localisation of this kinase.
AB - Multiple protein kinase C (PKC) θ species, identified in an erythroleukaemia cell line, have been characterised in terms of their molecular properties and intracellular distribution. PKCθs localised in the detergent-soluble cell fraction have an Mr of 76 kDa (θ-76) and contain Thr538 or pThr538 in the kinase activation loop. In contrast, PKCθs localised in the Golgi complex have an M r of 85 kDa (θ-85) and, although unphosphorylated at Thr 538, are catalytically active. Strikingly, only θ-76 species which are unphosphorylated at Thr538 can undergo autocatalytic conversion to θ-85. Moreover, a Thr538→Ala PKCθ mutant is constitutively localised in the Golgi complex, confirming that changes in the phosphorylation state of this residue play a pivotal role in the overall control of catalytic properties and localisation of this kinase.
KW - Erythroleukemia cell
KW - Golgi complex
KW - Protein kinase C θ phosphorylation
KW - Thr →Glu protein kinase Cθ
KW - Thr→Ala protein kinase Cθ
UR - http://www.scopus.com/inward/record.url?scp=0142246600&partnerID=8YFLogxK
U2 - 10.1016/S0014-5793(03)01073-1
DO - 10.1016/S0014-5793(03)01073-1
M3 - Article
SN - 0014-5793
VL - 554
SP - 35
EP - 40
JO - FEBS Letters
JF - FEBS Letters
IS - 1-2
ER -