The N-terminal domain influences the structure and property of protein phosphatase 1.
The protein phosphatase 1 has conserved cores in PPP gene family flanked by non-conserved N-terminal domains. PP1 with residues 1-8 deleted or substituted by residues 1-42 of calcineurin catalytic subunit were designated PP1-(9-330) and CNA(1-42)-PP1(9-330), respectively. When compared with PP1, PP1-(9-330) had higher and CNA(1-42)-PP1(9-330) had lower activity with three kinds of substrates; PP1-(9-330) has higher and CNA(1-42)-PP1(9-330) has lower sensitivity to okadaic acid. These results imply that the N-terminal residues influence the activity and sensitivity to inhibitors of PP1. PP1-(9-330), PP1, and CNA(1-42)-PP1(9-330) displayed increasing K (m) and decreasing V (max) with three kinds of substrates, which suggest that the N-terminal residues are connected with the substrates affinity and catalytic efficiency of PP1. PP1-(9-330) has higher and CNA(1-42)-PP1(9-330) has lower fluorescence intensity than PP1, and the emission wavelength maximum was blue-shifted from PP1 to PP1-(9-330) and red-shifted from PP1 to CNA(1-42)-PP1(9-330). Our findings provide evidence that the N-terminal domain is an important region influencing the structure and properties of PP1.
Xie
Xiu-Jie
XJ
Department of Biochemistry and Molecular Biology, Beijing Normal University, Beijing Key Laboratory, Beijing 100875, People's Republic of China.
Huang
Wei
W
Xue
Cheng-Zhe
CZ
Wei
Qun
Q
D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D019319:Okadaic Acid / Q000378:metabolism; D011487:Protein Conformation; D054645:Protein Phosphatase 1 / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
D019319:Okadaic Acid; D054645:Protein Phosphatase 1