IGF-2 Somatomediini A ja preptiini ( insuliinierityksen vahvistaja )

• Kromosomissa 11 on myös IGF2, INS-IGF2geeni. Katson tässä INS-IGF2 "read through" geeniä.

  Tässä II kromosomin kohdassa on kyse  "gene imprinting ilmiöstä " 
  
  

Gene summary for IGF2 Gene:

This gene encodes a member of the insulin family of polypeptide growth factors, which are involved in development and growth. It is an imprinted gene, expressed only from the paternal allele, and epigenetic changes at this locus are associated with Wilms tumour, Beckwith-Wiedemann syndrome, rhabdomyosarcoma, and Silver-Russell syndrome. A read-through INS-IGF2 gene exists, whose 5' region overlaps the INS gene and the 3' region overlaps this gene. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. (provided by RefSeq, Oct 2010)
GeneCards Summary for IGF2 Gene:

IGF2 (insulin-like growth factor 2 (somatomedin A)) is a protein-coding gene. Diseases associated with IGF2 include hypoglycemic coma, and osteochondrosis. GO annotations related to this gene include growth factor activity and insulin receptor binding. An important paralog of this gene is IGF1.
UniProtKB/Swiss-Prot: IGF2_HUMAN, P01344

Function: The insulin-like growth factors possess growth-promoting activity. In vitro, they are potent mitogens for cultured cells. IGF-II is influenced by placental lactogen and may play a role in fetal development

Function: Preptin undergoes glucose-mediated co-secretion with insulin, and acts as physiological amplifier of glucose-mediated insulin secretion. Exhibits osteogenic properties by increasing osteoblast mitogenic activity through phosphoactivation of MAPK1 and MAPK3
Gene Wiki entry for IGF2 (Insulin-like growth factor 2) 


Tämän IFG-2 geenin koodaman proteiini preproteiinimuodosta  tulee PREPTIINI molekyyli.

PREPTIN (34 aminohappoa)- löytyyhän tästäkin pätkästä tietoa! Se on jakso Asp(69)-Leu(102)  molekyylistä  pro-IGF-II. Siis ilmeisesti keskimmäinen pätkä molekyyliä   Se on osteoblasteja ja luunmineralisoitumsita  edistävä.

 https://www.ncbi.nlm.nih.gov/pubmed/16912056

Am J Physiol Endocrinol Metab. 2007 Jan;292(1):E117-22. Epub 2006 Aug 15.

Preptin, another peptide product of the pancreatic beta-cell, is osteogenic in vitro and in vivo.

Cornish J¹, Callon KE, Bava U, Watson M, Xu X, Lin JM, Chan VA, Grey AB, Naot D, Buchanan CM, Cooper GJ, Reid IR.

Abstract

Several hormones that regulate nutritional status also impact on bone metabolism. Preptin is a recently isolated 34-amino acid peptide hormone that is cosecreted with insulin and amylin from the pancreatic beta-cells. Preptin corresponds to Asp(69)-Leu(102) of pro-IGF-II. Increased circulating levels of a pro-IGF-II peptide complexed with IGF-binding protein-2 have been implicated in the high bone mass phenotype observed in patients with chronic hepatitis C infection. We have assessed preptin's activities on bone. Preptin dose-dependently stimulated the proliferation (cell number and DNA synthesis) of primary fetal rat osteoblasts and osteoblast-like cell lines at periphysiological concentrations (>10(-11) M). In addition, thymidine incorporation was stimulated in murine neonatal calvarial organ culture, likely reflecting the proliferation of cells from the osteoblast lineage. Preptin did not affect bone resorption in this model. Preptin induced phosphorylation of p42/p44 MAP kinases in osteoblastic cells in a dose-dependent manner (10(-8)-10(-10) M), and its proliferative effects on primary osteoblasts were blocked by MAP kinase kinase inhibitors. Preptin also reduced osteoblast apoptosis induced by serum deprivation, reducing the number of apoptotic cells by >20%. In vivo administration of preptin increased bone area and mineralizing surface in adult mice. These data demonstrate that preptin, which is cosecreted from the pancreatic beta-cell with amylin and insulin, is anabolic to bone and may contribute to the preservation of bone mass observed in hyperinsulinemic states such as obesity.

SOMATOMEDIINI: 

IFG-2 peptidi 180

Somatomedin A

        1 mgipmgksml vlltflafas cciaayrpse tlcggelvdt lqfvcgdrgf yfsrpasrvs
       61 rrsrgiveec cfrscdlall etycatpaks erdvstpptv lpdnfprypv gkffqydtwk
      121 qstqrlrrgl pallrarrgh vlakeleafr eakrhrplia lptqdpahgg appemasnrk 

IGF-2 propeptidi?
 

https://www.ncbi.nlm.nih.gov/protein/P01344.1

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