Mysterious gene functionally decoded

June 23, 2014, Kiel University

The protein BEM46 is found in all creatures having a nucleus. Mammals have several copies of this gene whereas fungus have only one copy. Some years ago the bem46 gene was named under the top ten of the "known-unknown genes". Scientists of Kiel University show for the first time the link between bem46 and reproduction as well as growth processes in fungus. These findings have been published online on June, 13th in the scientific magazine Eukaryotic Cell.

BEM46 proteins are evolutionary conserved, but their functions remain elusive. It was reported previously that the BEM46 protein in the fungus Neurospora crassa is targeted to the ER, and is essential for ascospore germination. "In the present study, we established a bem46 knock-out strain of N. crassa. This bem46 mutant exhibited ascospore germination lower than wild type, but much higher than the previously characterized bem46-overexpressing and RNAi lines", says Professor Kempken, senior scientist of the current study. Reinvestigation of the RNAi transformants revealed two types of alternative spliced bem46 mRNA, with expression of either type leading to loss of ascospore germination. The results indicate that the phenotype was not due to bem46 mRNA downregulation or loss, but caused by the alternative spliced mRNAs and their encoded peptides.

Using the N. crassa ortholog of the eisosomal protein PILA from Aspergillus nidulans, the scientists further demonstrated co-localization of BEM46 with eisosomes. Employing the yeast two-hybrid system, they identified a single interaction partner: the anthranilate synthase component two (trp-1). This interaction was confirmed in vivo by a split-YFP approach. The ∆trp-1 mutant showed reduced ascospore germination and increased indole production; bioinformatic tools were used to identify a putative auxin biosynthetic pathway. The involved genes exhibited varying transcriptional regulation among the different bem46 transformant and mutant strains. The team also investigated the strains' indole production in different developmental stages. "Our findings suggest that indole biosynthesis gene regulation was influenced by bem46 overexpression", says Professor Kempken. "Furthermore, we uncovered evidence of co-localization of BEM46 with the neutral amino acid transporter MTR."

Explore further: Scientists develop new approach to study how genetic variants affect gene expression

More information: Kollath-Leiß, K., Bönninger, C., Sardar, P. and Kempken, F. (2014): "BEM46 Shows Eisosomal Localization and Association with Tryptophan-Derived Auxin Pathway in Neurospora crassa." Eukaryotic Cell, dx.doi.org/10.1128/EC.00061-14

Related Stories

RaDAR guides proteins into the nucleus

May 22, 2014

A Ludwig Cancer Research study has identified a novel pathway by which proteins are actively and specifically shuttled into the nucleus of a cell. Published online today in Cell, the finding captures a precise molecular barcode ...

Researchers find mutation causing neurodegeneration

January 19, 2012

A Jackson Laboratory research team led by Professor and Howard Hughes Medical Investigator Susan Ackerman, Ph.D., has discovered a defect in the RNA splicing process in neurons that may contribute to neurological disease.

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.