Light-inducible gene HSP70B encodes a chloroplast-localized heat shock protein in Chlamydomonas reinhardtii
Light-inducible gene HSP70B encodes a chloroplast-localized heat shock protein in Chlamydomonas reinhardtii
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DOI：
10.1007/bf00040835
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发表时间：
1996-09-01
影响因子：
5.1
通讯作者：
Beck, CF
中科院分区：
文献类型：
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作者：
Drzymalla, C;Schroda, M;Beck, CF
莱茵衣藻核热休克基因HSP70 B可被热应激和光照诱导。通过任一环境线索的诱导导致HSP70 B蛋白的瞬时升高。在这里，我们描述的组织和HSP70B基因的核苷酸序列。推导的蛋白质表现出明显较高的同源性，原核HSP70比真核生物，包括胞浆HSP70 A的莱茵衣藻。如先前通过体外翻译所证明的，HSP70 B蛋白是用可裂解的前序列合成的。使用HSP70 B特异性抗体，这种热休克蛋白定位于叶绿体的细胞分级分离实验。一个基质的位置，建议由一个保守的序列基序的存在下，用于裂解的前序列的信号肽酶的基质。HSP70蛋白从各种生物体和不同的细胞隔室的氨基酸比对允许识别序列基序，这是诊断的叶绿体和蓝藻的HSP70。
The nuclear heat shock gene HSP70B of Chlamydomonas reinhardtii is inducible by heat stress and light. Induction by either environmental cue resulted in a transient elevation in HSP70B protein. Here we describe the organization and nucleotide sequence of the HSP70B gene. The deduced protein exhibits a distinctly higher homology to prokaryotic HSP70s than to those of eukaryotes, including the cytosolic HSP70A of Chlamydomonas reinhardtii. The HSP70B protein, as previously demonstrated by in vitro translation, is synthesized with a cleavable presequence. Using an HSP70B-specific antibody, this heat shock protein was localized to the chloroplast by cell fractionation experiments. A stromal location was suggested by the presence of a conserved sequence motif used for cleavage of presequences by a signal peptidase of the stroma. Amino acid alignments of HSP70 proteins from various organisms and different cellular compartments allowed the identification of sequence motifs, which are diagnostic for HSP70s of chloroplasts and cyanobacteria.