| First Author | Naylor DJ | Year | 1998 |
| Journal | J Biol Chem | Volume | 273 |
| Issue | 33 | Pages | 21169-77 |
| PubMed ID | 9694873 | Mgi Jnum | J:49134 |
| Mgi Id | MGI:1276758 | Doi | 10.1074/jbc.273.33.21169 |
| Citation | Naylor DJ, et al. (1998) Evidence for the existence of distinct mammalian cytosolic, microsomal, and two mitochondrial GrpE-like proteins, the Co-chaperones of specific Hsp70 members. J Biol Chem 273(33):21169-77 |
| abstractText | We previously reported the cDNA cloning and characterization of a mammalian mitochondrial GrpE protein ( approximately 21 kDa, mt-GrpE#1) and now provide evidence for the presence of distinct cytosolic (approximately 40 kDa), microsomal ( approximately 50 kDa), and additional mitochondrial ( approximately 22 kDa, mt-GrpE#2) GrpE-like members. While a cytosolic GrpE-like protein has recently been identified, the demonstration of both a microsomal and a second mitochon-drial GrpE-like member represents the first in any biological system. Investigation of the microsomal and two mitochondrial GrpE-like proteins revealed that they bound specifically to Escherichia coli DnaK, and the complexes formed were not disrupted in the presence of 0.5 M salt but were readily dissociated in the presence of 5 mM ATP. The functional integrity of mt-GrpE#1 and #2 was verified by their ability to specifically interact with and stimulate the ATPase activity of mammalian mitochondrial Hsp70 (mt-Hsp70). Analysis of the cDNA sequences encoding the two mammalian mitochondrial GrpE-like proteins revealed approximately 47% positional identity at the amino acid level, the presence of a highly conserved mitochondrial leader sequence, and putative destabilization elements within the 3'-untranslated region of the mt-GrpE#2 transcript which are not present in the mt-GrpE#1 transcript. A constitutive expression of both mitochondrial GrpE-like transcripts in 22 distinct mouse tissues was observed but possible different post-transcriptional regulation of the mt-GrpE#1 and #2 transcripts may confer a different expression pattern of the encoded proteins. |
