Mertk, a type I receptor tyrosine kinase and member of the TAM family of receptors, has important functions in promoting efferocytosis and resolving inflammation under physiological conditions. In recent years, Mertk has also been linked to pathophysiological roles in cancer, whereby, in several cancer types, including solid cancers and leukemia/lymphomas. Mertk contributes to oncogenic features of proliferation and cell survival as an oncogenic tyrosine kinase. In addition, Mertk expressed on macrophages, including tumor-associated macrophages, promotes immune evasion in cancer and is suggested to act akin to a myeloid checkpoint inhibitor that skews macrophages towards inhibitory phenotypes that suppress host T-cell anti-tumor immunity. In the present study, to better understand the post-translational regulation mechanisms controlling Mertk expression in monocytes/macrophages, we used a PMA-differentiated THP-1 cell model to interrogate the regulation of Mertk expression and developed a novel Mertk reporter cell line to study the intracellular trafficking of Mertk. We show that PMA treatment potently up-regulates Mertk as well as components of the ectodomain proteolytic processing platform ADAM17, whereas PMA differentially regulates the canonical Mertk ligands Gas6 and Pros1 (Gas6 is down-regulated and Pros1 is up-regulated). Under non-stimulated homeostatic conditions, Mertk in PMA-differentiated THP1 cells shows active constitutive proteolytic cleavage by the sequential activities of ADAM17 and the Presenilin/γ-secretase complex, indicating that Mertk is cleaved homeostatically by the combined sequential action of ADAM17 and γ-secretase, after which the cleaved intracellular fragment of Mertk is degraded in a proteasome-dependent mechanism. Using chimeric Flag-Mertk-EGFP-Myc reporter receptors, we confirm that inhibitors of γ-secretase and MG132, which inhibits the 26S proteasome, stabilize the intracellular fragment of Mertk without evidence of nuclear translocation. Finally, the treatment of cells with active γ-carboxylated Gas6, but not inactive Warfarin-treated non-γ-carboxylated Gas6, regulates a distinct proteolytic itinerary-involved receptor clearance and lysosomal proteolysis. Together, these results indicate that pleotropic and complex proteolytic activities regulate Mertk ectodomain cleavage as a homeostatic negative regulatory event to safeguard against the overactivation of Mertk.

To develop resilient crops it is necessary to understand the underlying genetics of climatic response. A strong association between stay-green and post-flowering drought tolerance in Sorghum has been established. Being a complex quantitative trait, Quantitative Trait Loci (QTL) mapping experiments of stay-green in Sorghum have been frequently performed. The objective of the current study was to find consensus genomic regions that control stay-green by integrating the QTLs mapped in previous studies. Meta-QTL analysis was performed to summarize 115 QTLs projected on the consensus map. The analysis generated 32 Meta-QTL regions within which candidate gene (CG) identification was undertaken. 7 candidate genes were identified using the markers tightly linked to the Meta-QTLs. The results from this study will facilitate future attempts aiming to improve and understand drought tolerance in Sorghum.

Glioblastoma multiforme (GBM) is classified as WHO grade IV Astrocytoma & is the most common highly aggressive form of primary brain tumor. Garde IV tumor are highly recurrent even after treatment, with patient survival rate is less than two years from the time of diagnosis. This might be due to overexpression of one of the factor such as ATP-binding cassette transporters (ABC transporters) responsible for drug resistance. ABCC transporter family a member of ABC transporter was found to mostly responsible for multi drug resistance (MDR) in cancer cells. On the other hand, heterogeneous nuclear ribonucleoprotein (hnRNP) an alternative splicing factor play different role in various cellular process such as nucleic acid metabolism, transcription and translation regulation, among them hnRNPA1 is best studied and its aberrant deregulation favor development of cancer. This study was focused on to study the function of hnRNPA1 in the expression analysis of ABCC transporter (responsible for MDR) in glioma cell lines. The expression of ABCC transporter (ABCC4 and ABCC6) gene was examined in two glioma cell line i.e. U87MG and T98G in normal and knockdown two alternative variants of hnRNPA1 by Quantitative Realtime PCR and Reverse Transcription PCR. We found that ABCC4 was significantly overexpressed in hnRNPA1 Variant 2 knockdown cells (si hnRNPA1 V2) in U87 (3-fold) and in T98G (18.34-fold), While hnRNPA1 Variant 1 knockdown cells (hnRNPA1 V1i) does not shows any significant effect. Further, the expression of ABCC6 was decreased in both hnRNPA1 V1i (0.40-fold) and hnRNPA1 V2i (0.48-fold) in U87. Reverse transcription based result were complemented with normal PCR based detection strategy after running in agarose gel for U87MG and T98G glioma cell line. Finally, this result indicates that hnRNPA1 an alternative splicing factor regulate the expression of ABCC4 and ABCC6 transporter which are responsible for multiple drug resistance in cancer. This information will help in future for the development of an alternative method for the treatment of drug resistance cases in brain tumor and other tumors by targeting hnRNPA1 splicing factor.