PSMB8

Chr 6AR

proteasome 20S subunit beta 8

Also known as: ALDD, D6S216, D6S216E, JMP, LMP7, NKJO, PRAAS1, PSMB5i

NCBI Gene: 5696 ENSG00000204264 UniProt: P28062

The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes a member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit. This gene is located in the class II region of the MHC (major histocompatibility complex). Expression of this gene is induced by gamma interferon and this gene product replaces catalytic subunit 3 (proteasome beta 5 subunit) in the immunoproteasome. Proteolytic processing is required to generate a mature subunit. Two alternative transcripts encoding two isoforms have been identified; both isoforms are processed to yield the same mature subunit. [provided by RefSeq, Jul 2008]

Primary Disease Associations & Inheritance

Proteasome-associated autoinflammatory syndrome 1 and digenic formsMIM #256040

187

ClinVar variants

Pathogenic / LP

0.02

pLI score

Active trials

Clinical Summary— PSMB8

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Population Constraint (gnomAD)

Low constraint (pLI 0.02) — loss-of-function variants are relatively tolerated in the population.

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ClinVar Variants

13 Pathogenic / Likely Pathogenic· 94 VUS of 187 total submissions

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Clinical Trials

1 active or recruiting trial — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.

0.78LOEUF

pLI 0.022

Z-score 2.14

OE 0.37 (0.19–0.78)

Tolerant

Typical tolerance to LoF variation

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.

0.65Z-score

OE missense 0.86 (0.74–0.99)

138 obs / 161.3 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.

LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.37 (0.19–0.78)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.86 (0.74–0.99)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.16

0≤1.21.6

LoF obs/exp: 5 / 13.5Missense obs/exp: 138 / 161.3Syn Z: -0.97