Expression, purification and biochemical characterization of the N-terminal regions of human TIG3 and HRASLS3 proteins.
Tarzarotene-induced gene 3 (TIG3) and HRAS-like suppressor (HRASLS3) are members of the HREV107 family of class II tumor suppressors, which are down-regulated in various cancer cells. TIG3 and HRASLS3 also exhibit phospholipase activities. Both proteins share a common domain architecture with hydrophilic N-terminal and hydrophobic C-terminal regions. The hydrophobic C-terminal region is important for tumor suppression. However, the function of the hydrophilic N-terminal region remains elusive. To facilitate biochemical characterizations of TIG3 and HRASLS3, we expressed and purified the N-terminal regions of TIG3 and HRASLS3, designated TIG3 (1-134) and HRASLS3 (1-133), in a bacterial system. We found that the N-terminal regions of TIG3 and HRASLS3 have calcium-independent phospholipase A(2) activities. Limited proteolysis revealed that TIG3 (1-132) is a structural domain in the N-terminal region of TIG3. Our data suggest that the hydrophobic C-terminal regions might be crucial for cellular localization, while the hydrophilic N-terminal regions are sufficient for the enzymatic activity of both TIG3 and HRASLS3.
Han
Byeong-Gu
BG
Cancer Cell and Molecular Biology Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang, Gyeonggi 410-769, Republic of Korea.
Cho
Jea-Won
JW
Cho
Young-Doo
YD
Kim
Soo-Youl
SY
Yoon
Hye-Jin
HJ
Song
Hyun Kyu
HK
Cheong
Hae-Kap
HK
Jeon
Young-Ho
YH
Lee
Dong-Ki
DK
Lee
Sangho
S
Lee
Byung Il
BI
D000595:Amino Acid Sequence; D001671:Biochemistry / Q000379:methods*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D054467:Phospholipases A2 / Q000378:metabolism; D054512:Phospholipases A2, Calcium-Independent; D017434:Protein Structure, Tertiary; D018168:Receptors, Retinoic Acid / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism
D047908:Intracellular Signaling Peptides and Proteins; C437968:PLAAT4 protein, human; D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; C490065:PLAAT3 protein, human; D054467:Phospholipases A2; D054512:Phospholipases A2, Calcium-Independent