A gene encoding the rice 16.9-kDa class I low-molecular-mass (LMM) heat-shock protein (HSP), Oshsp16.9, was introduced into Escherichia coli using the

No abstract

A rice class I low-molecular-mass heat shock protein (LMM HSP) Oshsp 16.9 was overexpressed in Escherichia coli. Oligomerized complexes of Oshsp16.9 were harvested and electron microscopic observations of purified complexes revealed globular structures of 10-20 nm in diameter (with majority of 15-18 nm) and calculated to comprise approx. 12 monomers per complex. In comparison, complexes from native rice class I LMM HSPs were observed as larger ellipsoid- or globular-like random aggregated hetero-oligomers. To characterize the biochemical functions of the hydrophobic N-terminal region of Oshsp16.9, a truncation in the N-terminal region was constructed and introduced into E. coli. Results showed that the N-terminal truncated Oshsp16.9 mutant was capable of forming complexes similar to the full-length Oshsp16.9; however, the deletion protein failed to confer in vitro protein thermostability under elevated temperatures. Protein assays from in vivo treatments at higher temperatures exhibited that non-specific interactions of E. coli cellular proteins only occurred with full-length Oshsp16.9 complexes but not with the mutant complex. In vitro immunoprecipitation of cellular proteins from E. coli overexpressing full-length Oshsp16.9 showed that interactions between plant LMM HSP and E. coli cellular proteins are temperature-dependent. Taken together, the hydrophobic N-terminal region of rice class I LMM HSP is critical in the ability of the protein to interact/bind with its potential substrates.

Germinomas in the central nervous system (CNS) are uncommon tumors and occur usually in the pineal or suprasellar regions. Primary spinal germinoma is extremely rare. Here we reported a rare case of an extramedullary germinoma in a young adult who presented with progressive paraparesis and retention of stool and urine. The MR image features with their differential diagnoses were discussed along with literature review of all previously reported 22 cases.

Plants synthesis multiple families of sHSPs with monomer sizes ranging from 12 to 42 kDa, are the most diverse and more abundant than in other organisms (Wu et al., 2022). In addition to heat tolerance, the sHSPs suggesting that they may play important roles other cellular processes under normal conditions (Wu et al., 2022). Over the past decades, it has been observed that the expression of certain plant sHSPs is induced by a range of stressors, including heat, salt, drought, osmotic, hormonal, heavy metal, oxidative stresses, as well as developmental signals specific to plants (Wu, et al. 2022). In addition, a multitude of investigation have involved the overexpression of various sHSPs in both homologous and heterologous plant systems, including E. coli and Yeast models (Santhanagopalan, et al. 2015; Waters and Vierling 2020). The outcomes of many of these experiments have revealed that stress protection conferred by these proteins is restricted to specific conditions and narrow range of plant growth stages. On contrast, suppression of CI or CII sHSPs in A. thaliana by RNAi showed that these sHSPs were required for recovery from a severe heat stress (10 h at 45°C) and have independent functions (McLoughlin, et al. 2016; Wu, et al. 2022). However, additional investigations are needed to uncover further applications for these proteins.