Starvation-induced posttranscriptional control of rat liver mitochondrial citrate carrier expression.
Starvation has been associated with a reduced citrate carrier (CTP) activity in rat liver mitochondria. In the present study the molecular mechanism responsible for this reduction was investigated. Northern blot analysis performed with hepatic total RNA showed a decrease of about 40% in the CTP mRNA abundance in starved rats, when compared to fed animals. Nuclear run-on assay did not reveal any appreciable difference in the rate of CTP mRNA synthesis between the two groups of animals, while the apparent half-life of CTP mRNA in hepatocytes from fed and starved rats was 11 and 6h, respectively. Therefore, these results suggest that in starved rats the regulation of hepatic CTP expression occurs at posttranscriptional level. Moreover, the reduced CTP activity in starved animals gradually increased by refeeding. The carrier activity reached fed rat values 6-9h following refeeding. Interestingly, the accumulation of CTP mRNA raised in parallel with the transport activity.
Siculella
Luisa
L
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Laboratorio di Biochimica, Università di Lecce, Via Prov. Lecce-Monteroni, Lecce, Italy.
Sabetta
Simona
S
di Summa
Roberta
R
Leo
Monica
M
Giudetti
Anna Maria
AM
Palmieri
Ferdinando
F
Gnoni
Gabriele Vincenzo
GV
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D010084:Oxidation-Reduction; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013217:Starvation / Q000378:metabolism*; D013997:Time Factors
D002352:Carrier Proteins; D012333:RNA, Messenger; C020723:citrate-binding transport protein