Pam17 and Tim44 act sequentially in protein import into the mitochondrial matrix.
Import of proteins into the matrix is driven by the Tim23 presequence translocase-associated import motor PAM. The core component of PAM is the mitochondrial chaperone mtHsp70, which ensures efficient translocation of proteins across the inner membrane through interactions with the J-protein complex Pam16-Pam18 (Tim16-Tim14) and its cochaperone Tim44. The recently identified non-essential Pam17 is a further member of PAM. Genetic and biochemical analyses reveal synthetic interactions between PAM17 and TIM44. Pam17 is involved in an early stage of protein translocation whereas Tim44 assists in a later step of transport, suggesting that both proteins can cooperate in a complementary manner in protein import.
Schiller
Dirk
D
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA. schiller@biochem.uni-frankfurt.de
D000252:Calcium-Transporting ATPases / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D018832:Molecular Chaperones / Q000378:metabolism; D010641:Phenotype; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000378:metabolism; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
D008565:Membrane Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D018832:Molecular Chaperones; C503873:Pam17 protein, S cerevisiae; D011498:Protein Precursors; C101767:SSC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C077016:TIM44 protein, S cerevisiae; D000252:Calcium-Transporting ATPases