Role of the heme regulatory motif in the heme-mediated inhibition of mitochondrial import of 5-aminolevulinate synthase

被引:85
作者
Munakata, H
Sun, JY
Yoshida, K
Nakatani, T
Honda, E
Hayakawa, S
Furuyama, K
Hayashi, N
机构
[1] Kinki Univ, Sch Med, Dept Biochem, Osaka 5898511, Japan
[2] Tohoku Univ, Sch Med, Dept Biochem, Aoba Ku, Sendai, Miyagi 9808575, Japan
关键词
aminolevulinate synthase; heme; mitochondrial import;
D O I
10.1093/jb/mvh112
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
5-Aminolevulinate synthase (ALAS) is a mitochondrial enzyme that catalyzes the first step of the heme biosynthetic pathway. The mitochondrial import, as well as the synthesis, of the nonspecific isoform of ALAS (ALAS1) is regulated by heme through a feedback mechanism. A short amino acid sequence, the heme regulatory motif (HRM), is known to be involved in the regulatory function of heme. To determine the role of the HRM in the heme-regulated transport of the nonspecific and erythroid forms of ALAS in vivo, we constructed a series of mutants of rat ALAS1, in which the cysteine residues in the three putative HRMs in the N-terminal region of the enzyme were converted to serine ones by site-directed mutagenesis. The wild-type and mutant enzymes were expressed in quail QT6 fibroblasts through transient transfection, and the mitochondrial import of these enzymes was examined in the presence of hemin. Hemin inhibited the mitochondrial import of wild-type ALAS1, but this inhibition was reversed on the mutation of all three HRMs in the enzyme, indicating that the HRMs are essential for the heme-mediated inhibition of ALAS1 transport in the cell. By contrast, exogenous hemin did not affect the mitochondrial import of the erythroid-specific ALAS isoform (AIAS2) under the same experimental conditions. These results may reflect the difference in the physiological functions of the two ALAS isoforms.
引用
收藏
页码:233 / 238
页数:6
相关论文
共 21 条
[1]   REGULATION OF THE STABILITY OF CHICKEN-EMBRYO LIVER DELTA-AMINOLEVULINATE SYNTHASE MESSENGER-RNA BY HEMIN [J].
DREW, PD ;
ADES, IZ .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1989, 162 (01) :102-107
[2]   Phylogenetic analysis of the 5-Aminolevulinate synthase gene [J].
Duncan, R ;
Faggart, MA ;
Roger, AJ ;
Cornell, NW .
MOLECULAR BIOLOGY AND EVOLUTION, 1999, 16 (03) :383-396
[3]   HEME-BIOSYNTHESIS - BIOCHEMISTRY, MOLECULAR-BIOLOGY, AND RELATIONSHIP TO DISEASE [J].
FERREIRA, GC .
JOURNAL OF BIOENERGETICS AND BIOMEMBRANES, 1995, 27 (02) :147-150
[4]   The solution structure and heme binding of the presequence of murine 5-aminolevulinate synthase [J].
Goodfellow, BJ ;
Dias, JS ;
Ferreira, GC ;
Henklein, P ;
Wray, V ;
Macedo, AL .
FEBS LETTERS, 2001, 505 (02) :325-331
[5]   INHIBITION BY HEMIN OF INVITRO TRANSLOCATION OF CHICKEN LIVER DELTA-AMINOLEVULINATE SYNTHASE INTO MITOCHONDRIA [J].
HAYASHI, N ;
WATANABE, N ;
KIKUCHI, G .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1983, 115 (02) :700-706
[6]   REGULATION BY HEME OF MITOCHONDRIAL PROTEIN-TRANSPORT THROUGH A CONSERVED AMINO-ACID MOTIF [J].
LATHROP, JT ;
TIMKO, MP .
SCIENCE, 1993, 259 (5094) :522-525
[7]  
LO SC, 1981, CANCER RES, V41, P864
[8]   Heme oxygenase-2 is a hemoprotein and binds heme through heme regulatory motifs that are not involved in heme catalysis [J].
McCoubrey, WK ;
Huang, TJ ;
Maines, MD .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1997, 272 (19) :12568-12574
[9]  
MELEFORS O, 1993, J BIOL CHEM, V268, P5974
[10]   PURIFICATION AND STRUCTURE OF RAT ERYTHROID-SPECIFIC DELTA-AMINOLEVULINATE SYNTHASE [J].
MUNAKATA, H ;
YAMAGAMI, T ;
NAGAI, T ;
YAMAMOTO, M ;
HAYASHI, N .
JOURNAL OF BIOCHEMISTRY, 1993, 114 (01) :103-111