title: The identification and characterization of IbpA, a novel α-crystallin-type heat shock protein from mycoplasma.
abstract: α-Crystallin-type small heat shock proteins (sHsps) are expressed in many bacteria, animals, plants, and archaea. Among mycoplasmas (Mollicutes), predicted sHsp homologues so far were found only in the Acholeplasmataceae family. In this report, we describe the cloning and functional characterization of a novel sHsp orthologue, IbpA protein, present in Acholeplasma laidlawii. Importantly, similar to the endogenously expressed sHsp proteins, the recombinant IbpA protein was able to spontaneously generate oligomers in vitro and to rescue chemically denatured bovine insulin from irreversible denaturation and aggregation. Collectively, these data suggest that IbpA is a bona fide member of the sHsps family. The immune-electron microscopy data using specific antibodies against IbpA have revealed different intracellular localization of this protein in A. laidlawii cells upon heat shock, which suggests that IbpA not only may participate in the stabilization of individual polypeptides, but may also play a protective role in the maintenance of various cellular structures upon temperature stress.
authors: Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russia.
authors: Innokentii E
authors: IE
authors: Vishnyakov
authors: Sergei A
authors: SA
authors: Levitskii
authors: Valentin A
authors: VA
authors: Manuvera
authors: Vassili N
authors: VN
authors: Lazarev
authors: Juan A
authors: JA
authors: Ayala
authors: Vadim A
authors: VA
authors: Ivanov
authors: Ekaterina S
authors: ES
authors: Snigirevskaya
authors: Yan Yu
authors: YY
authors: Komissarchik
authors: Sergei N
authors: SN
authors: Borchsenius
mesh_terms: D000128:Acholeplasma laidlawii / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D020869:Gene Expression Profiling; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006358:Hot Temperature; D015151:Immunoblotting; D007328:Insulin / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D038201:alpha-Crystallins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D006360:Heat-Shock Proteins; D007328:Insulin; D038201:alpha-Crystallins