MKRN3 Interacts With Several Proteins Implicated in Puberty Timing but Does Not Influence GNRH1 Expression.

Area of Science:

• Genetics and Developmental Biology
• Endocrinology
• Molecular Biology

Background:

• Paternally-inherited loss-of-function mutations in the makorin ring finger protein 3 (MKRN3) gene are a known cause of central precocious puberty.
• Understanding the precise molecular mechanisms by which MKRN3 influences puberty initiation in humans is crucial.

Purpose of the Study:

• To investigate the human-specific puberty-related mechanisms of the MKRN3 gene.
• To generate and characterize MKRN3 knock-out human pluripotent stem cell lines for neuronal differentiation.
• To identify protein-protein interaction partners of MKRN3.

Main Methods:

• Generation of two distinct bi-allelic MKRN3 knock-out human pluripotent stem cell lines (Del 1 and Del 2).
• Differentiation of these stem cells into GNRH1-expressing neurons.
• Stable expression of MKRN3 in HEK cells followed by mass spectrometry to identify protein-protein interactions (PPIs).

Main Results:

• MKRN3 knock-out stem cells successfully differentiated into GNRH1-expressing neurons, with no significant difference in GNRH1 expression compared to wild-type cells.
• Mass spectrometry identified 81 high-confidence novel protein interaction partners for MKRN3.
• Among the identified interactors, 20 proteins have known roles in regulating puberty timing, implicating pathways like insulin signaling, RNA metabolism, and cell-cell adhesion.

Conclusions:

• The generated stem cell model did not elucidate the role of MKRN3 in GNRH1 neuron development for puberty initiation.
• Protein-protein interaction data suggest MKRN3 may regulate puberty onset through interactions with other puberty-related proteins.
• Further research is necessary to fully understand the mechanisms and consequences of MKRN3 protein interactions in puberty regulation.