The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
Gene Review

hspX  -  alpha-crystallin

Mycobacterium tuberculosis H37Rv

Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of hspX

  • Deletion of the Mycobacterium tuberculosis alpha-crystallin-like hspX gene causes increased bacterial growth in vivo [1].

High impact information on hspX

  • A complete genomic microarray study demonstrated that SigC modulates the expression of several key virulence-associated genes including hspX, senX3 and mtrA, encoding the alpha-crystallin homologue, a two-component sensor kinase and a two-component response regulator respectively [2].
  • Changes in the mRNA levels of two Mycobacterium tuberculosis genes (fbpB known as antigen 85B, and hspX known as Acr) were studied in infected human monocytes [3].
  • The increased growth in macrophages was equal to that of a DeltadosR mutant, while introduction of a constitutively expressed hspX gene reduced the DeltadosR virulence to wild-type levels [1].
  • The use of M. smegmatis as a tool for studying the mycobacterial stringent response was demonstrated by measuring the expression of two M. tuberculosis genes, hspX and eis, in M. smegmatis in the presence and absence of rel(Msm) [4].
  • Primer extension analysis revealed that the transcription start site is located 33 nucleotides upstream of the hspX gene start codon [5].

Biological context of hspX

  • This study gives new insights into the expression profiles of the different mce operons and the hspX and esat-6 genes in an in vitro model of dormant-like bacilli [6].

Analytical, diagnostic and therapeutic context of hspX

  • Two transcripts of about 2.5 and 1.1 kb were demonstrated by Northern blot analysis and hybridized to the hspX gene probe [5].
  • In a timed sampling study, using a slowly stirred oxygen depletion culture model, we have demonstrated that the hspX mRNA that codes for Acr protein as well as the protein itself is induced just as the bacilli enter the microaerophilic NRP stage 1 (NRP-1) [7].
  • The RT-PCR results showed that mce-1a, mce-2a, hspX (encoding the alpha-crystallin antigen Acr) and esat-6 (encoding the early secretory antigenic target-6) were expressed throughout the cultivation period, whereas the expression of mce-3a and mce-4a was downregulated in the later stages of cultivation [6].
  • We also demonstrated that hspX, which is dependent on dosR for expression, is induced when cultures are left standing for 30 min, while significant but minor induction was seen following a 10 min centrifugation [8].


  1. Deletion of the Mycobacterium tuberculosis alpha-crystallin-like hspX gene causes increased bacterial growth in vivo. Hu, Y., Movahedzadeh, F., Stoker, N.G., Coates, A.R. Infect. Immun. (2006) [Pubmed]
  2. Mycobacterium tuberculosis ECF sigma factor sigC is required for lethality in mice and for the conditional expression of a defined gene set. Sun, R., Converse, P.J., Ko, C., Tyagi, S., Morrison, N.E., Bishai, W.R. Mol. Microbiol. (2004) [Pubmed]
  3. An increase in expression of a Mycobacterium tuberculosis mycolyl transferase gene (fbpB) occurs early after infection of human monocytes. Wilkinson, R.J., DesJardin, L.E., Islam, N., Gibson, B.M., Kanost, R.A., Wilkinson, K.A., Poelman, D., Eisenach, K.D., Toossi, Z. Mol. Microbiol. (2001) [Pubmed]
  4. The relA homolog of Mycobacterium smegmatis affects cell appearance, viability, and gene expression. Dahl, J.L., Arora, K., Boshoff, H.I., Whiteford, D.C., Pacheco, S.A., Walsh, O.J., Lau-Bonilla, D., Davis, W.B., Garza, A.G. J. Bacteriol. (2005) [Pubmed]
  5. Transcription of the stationary-phase-associated hspX gene of Mycobacterium tuberculosis is inversely related to synthesis of the 16-kilodalton protein. Hu, Y., Coates, A.R. J. Bacteriol. (1999) [Pubmed]
  6. Expression of the mceA, esat-6 and hspX genes in Mycobacterium tuberculosis and their responses to aerobic conditions and to restricted oxygen supply. Haile, Y., Bjune, G., Wiker, H.G. Microbiology (Reading, Engl.) (2002) [Pubmed]
  7. Microaerophilic induction of the alpha-crystallin chaperone protein homologue (hspX) mRNA of Mycobacterium tuberculosis. Desjardin, L.E., Hayes, L.G., Sohaskey, C.D., Wayne, L.G., Eisenach, K.D. J. Bacteriol. (2001) [Pubmed]
  8. The Mycobacterium tuberculosis dosRS two-component system is induced by multiple stresses. Kendall, S.L., Movahedzadeh, F., Rison, S.C., Wernisch, L., Parish, T., Duncan, K., Betts, J.C., Stoker, N.G. Tuberculosis (Edinburgh, Scotland) (2004) [Pubmed]
WikiGenes - Universities