Identification of a novel member of yeast mitochondrial Hsp70-associated motor and chaperone proteins that facilitates protein translocation across the inner membrane.
Here, we report the identification of yeast 15-kD Tim15/Zim17, a new member of mitochondrial Hsp70 (mtHsp70)-associated motor and chaperone (MMC) proteins. The 15-kD MMC protein is a peripheral inner membrane protein with a zinc-finger motif. Depletion of the 15-kD protein led to impaired import of presequence-containing proteins into the matrix in vivo and in vitro. Overexpression of the 15-kD protein rescued the functional defects of mtHsp70 in ssc1-3 cells, and a fusion protein containing the 15-kD protein physically interacts with purified mtHsp70. Tim15/Zim17 therefore cooperates with mtHsp70 to facilitate import of presequence-containing proteins into the matrix.
Yamamoto
Hayashi
H
Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
Momose
Takaki
T
Yatsukawa
Yoh-Ichi
Y
Ohshima
Chié
C
Ishikawa
Daigo
D
Sato
Takehiro
T
Tamura
Yasushi
Y
Ohwa
Yukimasa
Y
Endo
Toshiya
T
D000595:Amino Acid Sequence; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D018832:Molecular Chaperones / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
D018840:HSP70 Heat-Shock Proteins; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; C495990:Zim17 protein, S cerevisiae