TY - JOUR
T1 - Developmental regulation of heat shock protein 83 in Leishmania
T2 - 3′ processing and mRNA stability control transcript abundance, and translation is directed by a determinant in the 3′-untranslated region
AU - Zilka, Alon
AU - Garlapati, Srinivas
AU - Dahan, Edit
AU - Yaolsky, Victoria
AU - Shapira, Michal
PY - 2001/12/21
Y1 - 2001/12/21
N2 - Developmental gene regulation in trypanosomatids proceeds exclusively by post-transcriptional mechanisms. Stability and abundance of heat shock protein (HSP)70 and HSP83 transcripts in Leishmania increase at mammalian-like temperatures, and their translation is enhanced. Here we report that the 3′-untranslated region (UTR) of HSP83 (886 nucleotides) confers the temperature-dependent pattern of regulation on a chloramphenicol acetyltransferase (CAT) reporter transcript. We also show that the majority of the 3′-UTR sequences are required for increasing mRNA stability during heat shock. Processing of the HSP70 and HSP83 primary transcripts to poly(A)+ mRNA was more efficient during heat shock; therefore, even when stability at 33 °C was reduced by deletions in the 3′-UTR, transcripts still accumulated to comparable and even higher levels. Translation of heat shock transcripts in Leishmania increases dramatically upon temperature elevation. Unlike in other eukaryotes in which the 5′-UTR confers preferential translation on heat shock transcripts, we show that translational control of HSP83 in Leishmania originates from its 3′-UTR. The 5′-UTR alone cannot induce translation during heat shock, but it has a minor contribution when combined with the HSP83 3′-UTR. We identified an element located between positions 201 and 472 of the 3′-UTR which is essential for increasing translation of the CAT-HSP83 reporter RNA at 33-37 °C. This region confers preferential translation during heat shock even in transcripts that were less stable. Thus, investigating the traditionally conserved heat shock response reveals that Leishmania parasites use unique pathways for translational control.
AB - Developmental gene regulation in trypanosomatids proceeds exclusively by post-transcriptional mechanisms. Stability and abundance of heat shock protein (HSP)70 and HSP83 transcripts in Leishmania increase at mammalian-like temperatures, and their translation is enhanced. Here we report that the 3′-untranslated region (UTR) of HSP83 (886 nucleotides) confers the temperature-dependent pattern of regulation on a chloramphenicol acetyltransferase (CAT) reporter transcript. We also show that the majority of the 3′-UTR sequences are required for increasing mRNA stability during heat shock. Processing of the HSP70 and HSP83 primary transcripts to poly(A)+ mRNA was more efficient during heat shock; therefore, even when stability at 33 °C was reduced by deletions in the 3′-UTR, transcripts still accumulated to comparable and even higher levels. Translation of heat shock transcripts in Leishmania increases dramatically upon temperature elevation. Unlike in other eukaryotes in which the 5′-UTR confers preferential translation on heat shock transcripts, we show that translational control of HSP83 in Leishmania originates from its 3′-UTR. The 5′-UTR alone cannot induce translation during heat shock, but it has a minor contribution when combined with the HSP83 3′-UTR. We identified an element located between positions 201 and 472 of the 3′-UTR which is essential for increasing translation of the CAT-HSP83 reporter RNA at 33-37 °C. This region confers preferential translation during heat shock even in transcripts that were less stable. Thus, investigating the traditionally conserved heat shock response reveals that Leishmania parasites use unique pathways for translational control.
UR - http://www.scopus.com/inward/record.url?scp=0035930556&partnerID=8YFLogxK
U2 - 10.1074/jbc.M108271200
DO - 10.1074/jbc.M108271200
M3 - Article
C2 - 11598129
AN - SCOPUS:0035930556
SN - 0021-9258
VL - 276
SP - 47922
EP - 47929
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 51
ER -