Rattus norvegicus Spermatogenesis Colony-Forming Assays.

Knowledge gaps persist on signaling pathways and metabolic states in germ cells sufficient to support spermatogenesis independent of a somatic environment. Consequently, methods to culture mammalian stem cells through spermatogenesis in defined systems have not been established. Lack of success at culturing mammalian stem cells through spermatogenesis in defined systems reflects an inability to experimentally recapitulate biochemical events that develop in germ cells within the testis-specific seminiferous epithelium.

Spermatogonial Gene Networks Selectively Couple to Glutathione and Pentose Phosphate Metabolism but Not Cysteine Biosynthesis.

In adult males, spermatogonia maintain lifelong spermatozoa production for oocyte fertilization. To understand spermatogonial metabolism we compared gene profiles in rat spermatogonia to publicly available mouse, monkey, and human spermatogonial gene profiles. Interestingly, rat spermatogonia expressed metabolic control factors , , and Germline Foxa2 was enriched in Gfra1 and Gfra1 undifferentiated A-single spermatogonia.

Steric and Electronic Interactions at Gln154 in ZEITLUPE Induce Reorganization of the LOV Domain Dimer Interface.

Plants measure light quality, intensity, and duration to coordinate growth and development with daily and seasonal changes in environmental conditions; however, the molecular details linking photochemistry to signal transduction remain incomplete. Two closely related light, oxygen, or voltage (LOV) domain-containing photoreceptor proteins, ZEITLUPE (ZTL) and FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1), divergently regulate the protein stability of circadian clock and photoperiodic flowering components to mediate daily and seasonal development. Using structural approaches, we identified that mutations at the Gly46 position led to global rearrangements of the ZTL dimer interface in the isolated ZTL-LOV domain.

Kinetics of the LOV domain of ZEITLUPE determine its circadian function in .

A LOV (Light, Oxygen, or Voltage) domain containing blue-light photoreceptor ZEITLUPE (ZTL) directs circadian timing by degrading clock proteins in plants. Functions hinge upon allosteric differences coupled to the ZTL photocycle; however, structural and kinetic information was unavailable. Herein, we tune the ZTL photocycle over two orders of magnitude.

LOV-based optogenetic devices: light-driven modules to impart photoregulated control of cellular signaling.

The Light-Oxygen-Voltage domain family of proteins is widespread in biology where they impart sensory responses to signal transduction domains. The small, light responsive LOV modules offer a novel platform for the construction of optogenetic tools. Currently, the design and implementation of these devices is partially hindered by a lack of understanding of how light drives allosteric changes in protein conformation to activate diverse signal transduction domains.

Short LOV Proteins in Methylocystis Reveal Insight into LOV Domain Photocycle Mechanisms.

Light Oxygen Voltage (LOV) proteins are widely used in optogenetic devices, however universal signal transduction pathways and photocycle mechanisms remain elusive. In particular, short-LOV (sLOV) proteins have been discovered in bacteria and fungi, containing only the photoresponsive LOV element without any obvious signal transduction domains. These sLOV proteins may be ideal models for LOV domain function due to their ease of study as full-length proteins.

Zeitlupe senses blue-light fluence to mediate circadian timing in Arabidopsis thaliana.

Plants employ a variety of light, oxygen, voltage (LOV) domain photoreceptors to regulate diverse aspects of growth and development. The Zeitlupe (ZTL), Flavin-Kelch-Fbox-1 (FKF1), and LOV-Kelch-Protein-2 (LKP2) proteins dictate measurement of the day length, flowering time, and regulation of the circadian clock by blue-light regulation of protein complex formation. Previous reports indicated that ZTL photochemistry was irreversible, which is inconsistent with its role in marking the day-night transition.