Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1977-4-15
pubmed:abstractText
Low-speed centrifugation (640 g) of rat liver homogenates, prepared with a standard ionic medium, yielded a pellet from which a rapidly sedimenting fraction of rough endoplasmic reticulum (RSER) was recovered free of nuclei. This fraction contained 20-25% of cellular RNA and approximately 30% of total glucose-6-phosphatase (ER marker) activity. A major portion of total cytochrome c oxidase (mitochondrial marker) activity was also recovered in this fraction, with the remainder sedimenting between 640 and 6,000 g. Evidence is provided which indicates that RSER may be intimately associated with mitochondria. Complete dissociation of ER from mitochondria in the RSER fraction required very harsh conditions. Sucrose density gradient centrifugation analysis revealed that 95% dissociation could be achieved when the RSER fraction was first resuspended in buffer containing 500 mM KCl and 20 mM EDTA, and subjected to shearing. Excluding KCl, EDTA, or shearing from the procedure resulted in incomplete separation. Both electron microscopy and marker enzyme analysis of mitochondria purified by this procedure indicated that some structural damage and leakage of proteins from matrix and intermembrane compartments had occurred. Nevertheless, when mitochondria from RSER and postnuclear 6,000-g pellet fractions were purified in this way fromanimals injected with [35S]methionine +/- cycloheximide, mitochondria from the postnuclear 6,000-g pellet were found to incorporate approximately two times more cytoplasmically synthesized radioactive protein per milligram mitochondrial protein (or per unit cytochrome c oxidase activity) than did mitochondria from the RSER fraction. Mitochondria-RSER associations, therefore, do not appear to facilitate enhanced incorporation of mitochondrial proteins which are newly synthesized in the cytoplasm.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-1092698, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-13293190, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-13525433, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-13743151, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-13893456, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-13986422, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-14096433, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-14231448, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-14832284, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-14907713, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-4307201, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-4345164, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-4357366, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-4880002, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-5000179, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-5667361, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-5691970, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-6034775, http://linkedlifedata.com/resource/pubmed/commentcorrection/838772-838773
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9525
pubmed:author
pubmed:issnType
Print
pubmed:volume
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
714-25
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Two fractions of rough endoplasmic reticulum from rat liver. I. Recovery of rapidly sedimenting endoplasmic reticulum in association with mitochondria.
pubmed:publicationType
Journal Article