2bst

Structural highlights

Disease

[1B27_HUMAN] Defects in HLA-B are a cause of susceptibility to spondyloarthropathy type 1 (SPDA1) [MIM:106300]. It is a chronic rheumatic disease with multifactorial inheritance. It includes a spectrum of related disorders comprising ankylosing spondylitis, a subset of psoriatic arthritis, reactive arthritis (e.g. Reiter syndrome), arthritis associated with inflammatory bowel disease and undifferentiated spondyloarthropathy. These disorders may occur simultaneously or sequentially in the same patient, probably representing various phenotypic expressions of the same disease. Ankylosing spondylitis is the form of rheumatoid arthritis affecting the spine and is considered the prototype of seronegative spondyloarthropathies. It produces pain and stiffness as a result of inflammation of the sacroiliac, intervertebral, and costovertebral joints. Note=In the Greek Cypriot population, a restricted number of HLA-B27 subtypes are associated with ankylosing spondylitis and other B27-related diseases and an elevated frequency of the B*2702 allele in ankylosing spondylitis patients is identified. The allele B*2707 seems to have a protective role in this population because it was found only in the healthy controls.^[1]

Function

[1B27_HUMAN] Involved in the presentation of foreign antigens to the immune system. [Q8B2U6_9INFA] Encapsidates the negative strand viral RNA, protecting it from nucleases. The encapsidated genomic RNA is termed the ribonucleoprotein (RNP) and serves as template for transcription and replication. The RNP needs to be localized in the nucleus to start an infectious cycle, but is too large to diffuse through the nuclear pore complex. NP comprises at least 2 nuclear localization signals and is responsible of the active RNP import into the nucleus through the cellular importin alpha/beta pathway. Later in the infection, nucleus export of RNP are mediated through viral proteins NEP interacting with M1 which binds nucleoproteins. It is possible that the nucleoprotein binds directly exportin-1 (XPO1) and plays an active role in RNP nuclear export. M1 interaction with RNP seems to hide nucleoprotein's nuclear localization signals. Soon after a virion infects a new cell, M1 dissociates from the RNP under acidification of the virion driven by M2 protein. Dissociation of M1 from RNP unmask nucleoprotein's nuclear localization signals, targeting the RNP to the nucleus.[SAAS:SAAS00107710]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

• Beta-2 microglobulin
• Major histocompatibility complex

References

1. ↑ Varnavidou-Nicolaidou A, Karpasitou K, Georgiou D, Stylianou G, Kokkofitou A, Michalis C, Constantina C, Gregoriadou C, Kyriakides G. HLA-B27 in the Greek Cypriot population: distribution of subtypes in patients with ankylosing spondylitis and other HLA-B27-related diseases. The possible protective role of B*2707. Hum Immunol. 2004 Dec;65(12):1451-4. PMID:15603872 doi:10.1016/j.humimm.2004.08.177
2. ↑ Stewart-Jones GB, di Gleria K, Kollnberger S, McMichael AJ, Jones EY, Bowness P. Crystal structures and KIR3DL1 recognition of three immunodominant viral peptides complexed to HLA-B*2705. Eur J Immunol. 2005 Feb;35(2):341-51. PMID:15657948 doi:10.1002/eji.200425724