The Caenorhabditis elegans Shugoshin regulates TAC-1 in cilia.

The conserved Shugoshin (SGO) protein family is essential for mediating proper chromosome segregation from yeast to humans but has also been implicated in diverse roles outside of the nucleus. SGO's roles include inhibiting incorrect spindle attachment in the kinetochore, regulating the spindle assembly checkpoint (SAC), and ensuring centriole cohesion in the centrosome, all functions that involve different microtubule scaffolding structures in the cell. In Caenorhabditis elegans, a species with holocentric chromosomes, SGO-1 is not required for cohesin protection or spindle attachment but appears important for licensing meiotic recombination. Here we provide the first functional evidence that in C. elegans, Shugoshin functions in another extranuclear, microtubule-based structure, the primary cilium. We identify the centrosomal and microtubule-regulating transforming acidic coiled-coil protein, TACC/TAC-1, which also localizes to the basal body, as an SGO-1 binding protein. Genetic analyses indicate that TAC-1 activity must be maintained below a threshold at the ciliary base for correct cilia function, and that SGO-1 likely participates in constraining TAC-1 to the basal body by influencing the function of the transition zone 'ciliary gate'. This research expands our understanding of cellular functions of Shugoshin proteins and contributes to the growing examples of overlap between kinetochore, centrosome and cilia proteomes.

THYROIDITIS DEVELOPING POST INITIATION OF OCTREOTIDE IN A CASE OF TSH SECRETING TUMOR.

Thyroiditis developing post pituitary surgery in a case of TSH secreting tumor has been reported, albeit rarely. A 46 year old female was treated as a case of hypothyroidism for almost five years, however, TSH levels remained unsuppressed in spite of increasing thyroxine doses. A cyclic pattern of TSH with T3 secretion was observed after stopping thyroxine, though T4 levels were normal. T3 suppression test revealed a non suppressed TSH and MRI sella revealed a pituitary mass with Grade 1 cavernous sinus invasion. With a diagnosis of TSH secreting tumor, the patient was initiated on octreotide therapy. TFT normalized within 4 days of initiation of octreotide, tumor size reduced by about 30% within 2 months of therapy and goiter size reduced to almost half with octreotide therapy. Anti TPO levels which were initially negative became positive within a month of octreotide therapy and FNAC thyroid revealed thyroiditis. To the best of our knowledge, this is the second case report of development of thyroiditis after octreotide therapy. The immunomodulatory role of TSH and somatostatin may have a role in the development of thyroiditis in this case.