High impact information on SRP40

• Srp40p is a nonessential yeast nucleolar protein proposed to function as a chaperone for over 100 small nucleolar ribonucleoprotein particles that are required for rRNA maturation [1].
• SRP40 localizes to the yeast nucleolus and is required at a specific cellular concentration for optimal growth as indicated by the negative effect on cell growth of both overexpression and deletion of its gene [2].
• Growth defects, but no translocation or rRNA transcription/maturation phenotypes, were observed upon SRP40 inactivation or strong overexpression [3].
• SRP40 genetically interacts with four mutants affected in stable RNA synthesis and one mutant blocked in protein translocation to the endoplasmic reticulum [3].
• The yeast SRP40 gene product (Srp40p) is a highly serine-rich protein organized in three distinct domains [3].

Biological context of SRP40

• Comparison of the rat nucleolar protein nopp140 with its yeast homolog SRP40. Differential phosphorylation in vertebrates and yeast [2].
• While the parallels between these two proteins suggest that SRP40 is the bona fide yeast Nopp140 homolog, their disparities reflect the differences in nucleolar dynamics and regulation of ribosome biogenesis between yeast and vertebrates [2].

Analytical, diagnostic and therapeutic context of SRP40

• By indirect immunofluorescence microscopy, Srp40p localizes to punctate, sometimes fibrillar, subnuclear structures that might include the nucleolus [3].

References