Almost all eukaryotic mRNAs have a poly (A) tail at the 3′-end. Canonical PAPs (PAPα/γ) polyadenylate nuclear pre-mRNAs. The recent identification of the non-canonical Star-PAP revealed specificity of nuclear PAPs for pre-mRNAs, yet the mechanism how Star-PAP selects mRNA targets is still elusive. Moreover, how Star-PAP target mRNAs having canonical AAUAAA signal are not regulated by PAPα is unclear. We investigate specificity mechanisms of Star-PAP that selects pre-mRNA targets for polyadenylation. Star-PAP assembles distinct 3′-end processing complex and controls pre-mRNAs independent of PAPα. We identified a Star-PAP recognition nucleotide motif and showed that suboptimal DSE on Star-PAP target pre-mRNA 3′-UTRs inhibit CstF-64 binding, thus preventing PAPα recruitment onto it. Altering 3′-UTR cis-elements on a Star-PAP target pre-mRNA can switch the regulatory PAP from Star-PAP to PAPα. Our results suggest a mechanism of poly (A) site selection that has potential implication on the regulation of alternative polyadenylation.

Plasma level of cyclophilin A is a promising marker of vascular disease in patients with type 2 diabetes. Genetic variants in the peptidylprolyl isomerase A gene, encoding human cyclophilin may alter protein synthesis thus affecting its activity, function, and circulating plasma levels. We examined the effect of single-nucleotide polymorphisms (SNPs) within the PPIA gene on plasma levels of cyclophilin A and coupled this with status of vascular disease in patients with and without type 2 diabetes in 212 South Indian subjects. The regulatory region of PPIA gene was sequenced for SNPs. The association of SNPs with known blood markers of type 2 diabetes and coronary artery disease such as HbA1c, low- and high-density lipoproteins, triglycerides, fasting and postprandial blood sugar levels, and cyclophilin A were probed. We identified three SNPs namely, rs6850: A > G; (AG/-) c.*227_*228delAG and (-/T) c.*318_*319insT. Welchs two-sample t test indicated an association of SNP rs6850: A > G, located at the 5' UTR region with increased plasma levels of cyclophilin A in patients with coronary artery disease and with coronary artery disease associated with diabetes. The presence of rs6850: A > G variant was significantly associated with coronary artery disease irrespective of whether the patients had diabetes or not. In silico analysis of the sequence using different tools and matrix libraries did not predict any significant differential binding sites for rs6850: A > G, c.*227_*228delAG and c.*318_*319insT. Our results indicate that the SNP rs6850: A > G is associated with increased risk for elevated plasma levels of cyclophilin A and coronary artery disease in patients with and without type 2 diabetes.

<p class="abstract">Hemangioma is a benign, rapidly growing solitary lesion that usually occurs in the skin and mucous membrane. The exact etiology of such a lesion is unknown, but thought to be due to trauma and hormonal factors. Sinonasal hemangiomas are rare. Bleeding and nasal obstruction with mass sometimes filling the nasal cavity are the usual clinical presentation of such a lesion. We report a case of 42-year-old female with right nasal hemangioma presented with on and off epistaxis and progressive right-sided nasal obstruction. Examination of nasal cavity physically combined with endoscopy revealed a polypoid, reddish colored mass in the nasal cavity on the right side arising from septum. Endoscopic subperichondrfial excision was done under local anaesthesia. The histopathology showed vascular proliferative lesion, consistent with hemangioma. Endoscopic excision is preferred as it helps in better visualization. Subperichondrial excision helps to reduce bleeding also, prevent the recurrence. Although rare, the diagnosis of hemangioma must always be kept in mind while discussing the differential diagnosis of a bleeding mass in the nasal cavity.</p>

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