Jennifer D Ly

Monash University (Australia) · Faculty of Medicine, Nursing and Health Sciences

We previously showed that increased intracellular calcium can modulate Importin (Imp)β1-dependent nuclear import of SRY-related chromatin remodeling proteins. Here we extend this work to show for the first time that high intracellular calcium inhibits Impα/β1- or Impβ1-dependent nuclear protein import generally. The basis of this relates to the mis...

A key factor in oncogenesis is the transport into the nucleus of oncogenic signalling molecules, such as Gli1 (Glioma-associated oncogene homolog 1), the central transcriptional activator in the Hedgehog signalling pathway. Little is known, however, how factors such as Gli are transported into the nucleus, and how this may be regulated by interacti...

The importin (IMP) superfamily of nuclear transport proteins is essential to key developmental pathways, including in the murine testis where expression of the 6 distinct IMPα proteins is highly dynamic. Present predominantly from the spermatocyte stage onwards, IMPα4 is unique in showing a striking nuclear localization, a property we previously fo...

Spermatogenesis, the process of generating haploid sperm capable of fertilizing the female gamete, requires the timely transport into the nucleus of transcription and chromatin-remodeling factors, mediated by members of the importin (IMP) superfamily. Previous IMP expression profiling implies a role for IMPalpha2 in testicular germ cells late in sp...

Spermatogenesis, the progressive maturation of immature germ cells to form spermatozoa, requires nucleocytoplasmic shuttling of nuclear factors to implement changes in gene transcription, as well as the storage and alternative splicing of mRNA transcripts in the nucleus that is vital for fertility. The key cellular mediators of nuclear entry are me...

The polymerase accessory protein of the human herpes simplex virus type 1 (HSV-1) DNA polymerase UL42 plays an essential role in viral replication, conferring processivity to the catalytic subunit UL30. We show here that UL42 is imported to the nucleus of living cells in a Ran- and energy-dependent fashion, through a process that requires a C-termi...

Spermatogenesis, the complex process of generating haploid sperm capable of fertilising the female gamete, requires precisely scheduled transport into the nucleus of transcription factors and chromatin remodelling factors to implement changes in nuclear gene expression, as well as genome compaction during sperm formation (spermiogenesis). This tran...

Spermatogenesis, the morphogenetic process of generating haploid sperm capable of fertilising the female gamete, requires transport into the nucleus of transcription and chromatin remodelling factors to implement genome compaction. This transport is mediated by members of the importin (IMP) superfamily, which exhibit distinct expression patterns du...

Spermatogenesis, the differentiation process resulting in the production of haploid germ cells able to fertilise an oocyte, is driven by nuclear transcription factors, and changes in nuclear morphology and function itself. Signal-dependent transport into and out of the nucleus is mediated by members of the importin (IMP) superfamily of transporters...

Cysteine-rich secretory protein 2 (CRISP2) is a testis-enriched protein localized to the sperm acrosome and tail. CRISP2 has been proposed to play a critical role in spermatogenesis and male fertility, although the precise function(s) of CRISP2 remains to be determined. Recent data have shown that the CRISP domain of the mouse CRISP2 has the abilit...

Access to nuclear genes in eukaryotes is provided by members of the importin (IMP) superfamily of proteins, which are of alpha- or beta-types, the best understood nuclear import pathway being mediated by a heterodimer of an IMP alpha and IMP beta1. IMP alpha recognises specific targeting signals on cargo proteins, while IMP beta1 mediates passage i...

Spermatogenesis requires progression of germ line stem cells through a precisely ordered differentiation pathway to form spermatozoa. Diverse and dynamic signals from the transforming growth factor-beta (TGF-beta) superfamily influence many stages of germ cell development. For example, interactions between several TGF-beta superfamily ligands (bone...

Spermatogenesis is a unique, ordered process governed by the precise expression of a specific set of genes at each stage. Progression through successive stages requires the shuttling of proteins and transcription factors into and out of the nucleus to implement changes in gene transcription. Major factors that mediate nucleocytoplasmic transport ar...

The eukaryotic porin or voltage-dependent anion-selective channel (VDAC1) is a pore-forming protein discovered twenty five years ago in the mitochondrial outer membrane. Its gene in eukaryotes is known, but its tertiary structure has never been solved. Structure predictions highlight the presence of several amphipathic beta-strands possibly organis...

Porin isoform 1 or VDAC (voltage-dependent anion-selective channel) 1 is the predominant protein in the outer mitochondrial membrane. We demonstrated previously that a plasma membrane NADH-ferricyanide reductase activity becomes up-regulated upon mitochondrial perturbation, and therefore suggested that it functions as a cellular redox sensor. VDAC1...

We have recently demonstrated that voltage dependent anion selective channel~1 (porin, isoform 1) can function as a transplasma membrane NADH:ferricyanide-reductase. However, both the specific redox characteristics and the mechanism of electron transport in this enzyme presently remain unclear. Here we demonstrate that the redox capability of porin...

Mitochondrial dysfunction has been shown to participate in the induction of apoptosis and has even been suggested to be central to the apoptotic pathway. Indeed, opening of the mitochondrial permeability transition pore has been demonstrated to induce depolarization of the transmembrane potential (deltapsi(m)), release of apoptogenic factors and lo...

The notion of transmembrane electron transport is usually associated with mitochondria and chloroplasts. However, since the early 1970s, it has been known that this phenomenon also occurs at the level of the plasma membrane. Ever since, evidence has accumulated for the existence of a plethora of transplasma membrane electron transport enzymes. In t...

Permeability transition, and a subsequent drop in mitochondrial membrane potential (DeltaPsi(m)), have been suggested to be mechanisms by which cytochrome c is released from the mitochondria into the cytosol during apoptosis. Furthermore, a drop in DeltaPsi(m) has been suggested to be an obligate early step in the apoptotic pathway. Didemnin B, a b...