PIP5K1A & PSMD4-like protein; PIP5K1A-PSMD4 (PIPSL, PSMD4P2)

Function

• negligeable PIP5 kinase activity.
• binds to ubiquitinated proteins

Structure

• contains 1 PI5K domain
• contains 2 UIM (ubiquitin-interacting motif) repeats
• contains 1 VWFA domain

Compartment

cytoplasm

Expression

testis-specific

Evolution

• PIPSL gene appeared in hominoids by L1-mediated retrotransposition in a hominoid ancestor of a readthrough, intergenically spliced transcript between the PIP5K1A & PSMD4 genes

Notes

• could be the product of a pseudogene
• although transcribed, the gene is poorly tranlated probably due to a deletion in the regulatory region
• not detected by Western blot

More general terms

• testis-specific protein

Database

• UniProt: http://www.uniprot.org/uniprot/A2A3N6.html