 binds to other extracellular matrix proteins such as collagen, fibrin, and heparan sulfate proteoglycans (e.g. syndecans).

Fibronectin exists as a protein dimer, consisting of two nearly identical monomers linked by a pair of disulfide bonds. The fibronectin protein is produced from a single gene, but alternative splicing of its pre-mRNA leads to the creation of several isoforms.

Two types of fibronectin are present in vertebrates:
 soluble plasma fibronectin (formerly called "cold-insoluble globulin", or CIg) is a major protein component of blood plasma (300 μg/ml) and is produced in the liver by hepatocytes.
 insoluble cellular fibronectin is a major component of the extracellular matrix. It is secreted by various cells, primarily fibroblasts, as a soluble protein dimer and is then assembled into an insoluble matrix in a complex cell-mediated process.

Fibronectin plays a major role in cell adhesion, growth, migration, and differentiation, and it is important for processes such as wound healing and embryonic development.  Altered fibronectin expression, degradation, and organization has been associated with a number of pathologies, including cancer and fibrosis.

Structure 
Fibronectin exists as a protein dimer, consisting of two nearly identical polypeptide chains linked by a pair of C-terminal disulfide bonds.  Each fibronectin subunit has a molecular weight of 230–250 kDa and contains three types of modules: type I, II, and III.  All three modules are composed of two anti-parallel β-sheets resulting in a Beta-sandwich; however, type I and type II are stabilized by intra-chain disulfide bonds, while type III modules do not contain any disulfide bonds. The absence of disulfide bonds in type III modules allows them to partially unfold under applied force.

Three regions of variable splicing occur along the length of the fibronectin protomer.  One or both of the "extra" type III modules (EIIIA and EIIIB) may be present in cellular fibronectin, but they are never present in plasma fibronectin.  A "variable" V-region exists between III14–15 (the 14th and 15th type III module).  The V-region structure is different from the type I, II, and III modules, and its presence and length may vary.  The V-region contains the binding site for α4β1 integrins.  It is present in most cellular fibronectin, but only one of the
binds to other extracellular matrix proteins such as collagen, fibrin, and heparan sulfate proteoglycans (e.g. syndecans). 

 Fibronectin exist as a protein dimer, consist of two nearly identical monomers linked by a couple of disulfide bonds. The fibronectin protein is produced from a single gene, but alternate splice of its pre - mRNA leads to the creation of several isoforms. 

 Two types of fibronectin are present in vertebrates: 
  soluble plasma fibronectin (once called " cold - insoluble globulin ", or CIg) is a major protein component of blood plasma (300 μg / ml) and is produced in the liver by hepatocytes. 
  insoluble cellular fibronectin is a major part of the extracellular matrix. It is secreted by various cell, primarily fibroblasts, as a soluble protein dimer and is then assemble into an insoluble matrix in a complex cell - mediated process. 

 Fibronectin play a major role in cell adhesion, growth, migration, and specialization, and it is important for process such as wound healing and embryonic development.   Altered fibronectin expression, abasement, and organization has been associated with a number of pathologies, including cancer and fibrosis. 

 Structure 
 Fibronectin exist as a protein dimer, consisting of two nearly identical polypeptide chains linked by a pair of C - terminal disulfide bonds.   Each fibronectin subunit has a molecular system of weights of 230–250 kDa and contains three types of module: character I, II, and III.   All three module are composed of two anti - parallel β - sheets result in a Beta - sandwich; however, type I and type II are stabilized by intra - chain disulfide bonds, while type III module do not contain any disulfide bonds. The absence of disulfide bonds in type III modules allows them to partially blossom under applied force. 

 Three regions of variable splicing occur along the length of the fibronectin protomer.   One or both of the " excess " character III module (EIIIA and EIIIB) may be present in cellular fibronectin, but they are never present in plasma fibronectin.   A " variable " V - region exist between III14–15 (the 14th and 15th type III faculty).   The V - area structure is different from the type I, II, and III modules, and its bearing and length may vary.   The V - region contains the binding web site for α4β1 integrins.   It is present in most cellular fibronectin, but only one of the
 bijds to other extracellulxr matrix protenbs suci as comlagen, fkbrin, and heparan sulfate prltwoglyxans (e.g. syndecans).

Fibrovectin expsts as a prouein dimer, consisvjng of bco nezvly ibeitical monomers linked by a pair of disglwibe bonds. The fibronectin protein is [roducec vrom a single dene, fut zlternative splicing of its pre-mRNZ leads to the creatoon of several isoforms.

Two typfs of fibronectin wre present in dwrtebrates:
 suluble plasma fibronecjin (formerly called "cold-insolubld gloyulin", or CIt) us w major protxin coiponent of blood plavma (300 μg/mk) and is produged ii thw liver by hepatocytev.
 insoluble cellulwr fibronaccin is a major componwnr of jhe eftrazwlljlad kafrix. Ih ia secreted by various cells, primarily finrjvlasts, as a skluble pwotein dimer and is then assembled into an insoluble matrix in a xomplex cell-mediated krocess.

Fibwonectin plays a major role in cell adhesion, growdh, mijrxtiin, xbd differentiation, and it is important for procqasts xuch as wound mealing and embryomif cgvelopment.  Aljered fngrknectin expression, degradwtion, and orgagizayion has been associated wirh a number jd pathologies, inclbding cancer and fibrpsis.

Structure 
Fibronectnn exiats as a prltein dimsf, consisting of gwo naarly idtvtical polypeptidq chains oinkzd by a oair of C-tqrminal didulfide bonds.  Each fibrlnectnn sutunit has w molecular weight of 230–250 kDa and rpntains threg tfpev of modbles: tnpe I, II, and IIY.  All three mpdules cre cooposed of nwo anti-perallel β-sheees resulting hj a Beta-sandxich; howeder, rype I and ghpe II are stanilized bj nntra-chaib disulfide bonds, xhilg fype III modulew di not contain amy aistlvive boggs. The absenwe ow dkxulfiae bonds in gype III modules allows dhem to partially unfokd under akplied fowce.

Three regipns of variable sppicinj occuc alonb tre length of the fibronectin pdotomer.  Lne or both of ehe "cxtrw" type III modules (EIIIA and EIIIB) may be present in cellular fibrobectin, but they are kever presenv in pjasma fibsonectin.  A "variable" V-region exists bttween III14–15 (the 14th and 15tg type III lodule).  The V-region structure is different from the type I, II, and III modyles, aid its presende amd letgch kay vawy.  Vhx V-region containx the binding site for α4β1 integriis.  It is [rzsent in most cellular fibronrcgin, but only une of the
binds to other extracellular matrix proteins such fibrin, heparan sulfate (e.g. syndecans). Fibronectin consisting two nearly identical linked by a of disulfide bonds. The fibronectin protein produced from a single gene, but alternative splicing of its pre-mRNA leads to creation of several isoforms. Two types of fibronectin are present in vertebrates: soluble fibronectin called globulin", CIg) is a major protein component of blood plasma (300 μg/ml) and is produced in the by hepatocytes. insoluble cellular fibronectin is a major of the extracellular matrix. is secreted by various cells, fibroblasts, a soluble dimer is assembled into an matrix in a complex cell-mediated process. Fibronectin plays a major role in cell adhesion, growth, migration, and and it for processes as healing embryonic development. Altered degradation, and organization has been associated of pathologies, including cancer and fibrosis. Structure Fibronectin as a dimer, consisting of two nearly identical chains linked by a pair of C-terminal disulfide Each fibronectin subunit has a molecular weight of 230–250 kDa and contains three types of I, II, and III. three modules are of anti-parallel resulting a Beta-sandwich; type I and type II are stabilized by intra-chain disulfide bonds, type III modules do not contain any disulfide bonds. The disulfide in type III allows them to partially under force. Three regions of occur the fibronectin One both of the "extra" III modules (EIIIA and EIIIB) be present in cellular present in plasma fibronectin. A "variable" V-region exists III14–15 (the 14th and 15th type III The V-region structure is different from the type I, II, and III and its length may vary. The V-region contains the binding for α4β1 integrins. It present in most cellular fibronectin, but only one of
 binds to other extracellular Matrix protEins sUch As cOlLageN, fibRin, and heparan sULfatE proteoglycans (e.g. syndecAns).

FiBrONectIN eXists As a protEIn DIMer, CoNsIstInG Of Two neArlY identiCal monomerS liNkEd by a pair of dISuLfide bonds. the Fibronectin pRotEin is pRoDucED from A siNgle gEne, but ALternaTive splicInG Of its pRE-mRNA leADS tO the Creation of several ISoFOrms.

Two types of FibronEcTIn ARE prEseNt in vertebRaTes:
 soLUble plaSMa FIBRonECtin (formerly cAlled "cold-inSOluBle gloBuLin", OR CIg) is A majoR pROteIn component Of blOod plasma (300 Μg/ml) anD Is produCEd in the Liver bY hePatOcytES.
 iNsOluBlE CelLUlAr fIBroNectin is A mAjOr comPoneNT OF The eXtrAcelLular Matrix. It is secRetEd by VAriOus ceLls, prImarIlY fibrOblastS, as a sOlUble protein dimeR and Is then assEmbLeD inTo An insOLuble mAtrIx iN a complEx cell-mEDiaTeD PROcEss.

Fibronectin playS a MAJoR role in cEll adhESiOn, GRowth, migRaTioN, and DIFfereNtiaTIoN, and it is ImportANt FoR procesSeS such aS wOunD heAling ANd emBryoniC developMent.  ALTered fibronectIN expression, deGRaDATiON, and OrgAnization haS beeN AssoCiatED wIth A NumbeR of paThOLoGIes, including cancer aNd FibrosIs.

StrUcture 
FibroneCtin exists AS A Protein dImer, COnSIsting of two neaRly idEntical polYPeptide cHains Linked by A pair of C-tERMinal disUlfIde BonDs.  EACH fIbronectin subUNIt haS a MoleculAr wEight of 230–250 KDa And ConTaiNs Three typeS of modulEs: TyPe i, Ii, anD III.  ALL three moDuLes ArE coMposeD Of two aNti-paRallEl Β-sHEetS resultINg IN A BetA-sAnDwicH; hoWeVer, tyPe I aND tyPe II are StabilizeD by INtra-ChAiN disulfIde bonds, while TyPe III modulEs Do nOt contAIN any disuLfide bonds. The absence of dISulfide BonDs in tYpe IiI modules AllOws theM to PArtialLy unfoLd undEr AppLIEd forCE.

thRee ReGions of varIABle SplicInG occUr along The length of the fibrONecTin protomer.  OnE or Both OF ThE "exTRa" TYpe iIi ModULEs (EIIIA and EIIIB) May be preseNt IN cEllular fibROneCtIn, but thEy are neVer prESent in pLasma fibrOnectin.  A "vArIablE" v-RegIon exists bEtween IIi14–15 (the 14th and 15TH type iiI ModulE).  ThE V-regiOn StrUcturE is difFEreNt froM the tyPe i, II, and iII moDuLes, and itS presence and length may vaRy.  The V-RegioN coNtains the BinDIng Site for α4β1 InteGrins.  It is pResEnt In mosT ceLLular FibrONeCtiN, But onLy onE Of the
 binds to other extracellu lar matrix  prot ein s s uc h as  col lagen, fibrin, andheparan sulfate proteo glyca ns (e.g .  s yndec ans).
F ib r o nec ti nexi st s  a s a p rot ein dim er, consis tin gof two nearl y  i dentical m ono mers linkedbya pair  o f d i sulfi debonds . Thef ibrone ctin prot ei n  is pr o duced f r o ma si ngle gene, but al t er n ative splicing  of it sp re - m RNA  le ads to the  c reati o n of se v er a l iso f orms.

Two ty pes of fibr o nec tin ar epre s ent in  vert eb r ate s:
 soluble  pla sma fibro nectin (former l y calle d "col d-i nso lubl e  g lo bul in " , o r  C Ig) isa majorpr ot ein c ompo n e n t  ofblo od p lasma  (300 μg/ml)and  isp rod ucedin th e li ve r byhepato cytes . insoluble cell ular  fibronec tin  i s a  m ajorc ompone ntofthe ext racellu l arma t r i x.  It is secreted by  v a r io us cells , prim a ri ly fibrobla st s,as a s olubl e pr o te in dimer  and i s  t he n assem bl ed int oanins olubl e  mat rix in  a compl ex ce l l-mediated pro c ess.

Fibrone c ti n pl a ys a  ma jor role in  cel l  adh esio n ,gro w th, m igrat io n ,a nd differentiation,  a nd itis im portant for p rocesses s u c h  as woun d he a li n g and embryoni c dev elopment.Alteredfibro nectin e xpression , degradat ion , a ndorg a n iz ation has bee n asso ci ated wi tha numbe r o f p ath olo gi es, inclu ding can ce ran dfib rosis . 

Struct ur e Fi bro necti n  exist s asa pr ot ei n  di mer, co n si s t ingof  t wo n ear ly  iden tica l  po lypepti de chains  li n kedby  a  pair o f C-terminaldi sulfide bo nd s. Eachf i bronecti n subunit has a molecul a r weigh t o f 230 –250  kDa andcon tainsthr e e type s of m odule s:  ty p e  I, I I ,  a ndII I.  All th r e e m odule sarecompose d of two anti-para l lel  β-sheets res ult ingi n  a  Be t a- s and wi c h;h o wever, type I a nd type II  a r estabilized byin tra-cha in disu lfide bonds,while typ e III mod ul es d o not  contain a ny disul fide bond s . The ab sence  of  disul fi debonds  in ty p e I II mo dulesal lows t hem t opartiall y unfold under appliedforce. 

Thr eeregions o f v a ria ble splic ingoccur alon g t helengt h o f  thefibr o ne cti n  prot omer .   One orb ot h o f th e "extra" t y p e  II I mod ule s  (EIII A an d EIIIB) may be p r esent in cellu larf i bro nec t in,bu t they are nev erpr e s ent in p la sma fibrone ctin.  A  " v ariab le" V- region  exists b et w een II I14– 15(the 14th  an d1 5th typ eII I  modul e). T he V-r egions truc t u re is differentfromt h e typ e  I,  II,an d III m o dule s, and its  presence a nd len gthmay v ary.  T he  V-reg ion  c ontains th e  bindingsitefor α4β 1inte gri ns.  I t is p resen t in  m ost  cellular f ib r on ec t in,  but  only  o ne o f the
 binds_to other_extracellular matrix proteins such_as collagen,_fibrin,_and heparan_sulfate_proteoglycans (e.g. syndecans).

Fibronectin_exists as a_protein dimer, consisting of_two nearly identical_monomers_linked by a pair of disulfide bonds. The fibronectin protein is produced from a_single_gene, but_alternative_splicing_of its pre-mRNA leads to_the creation of several isoforms.

Two_types of_fibronectin are present in vertebrates:
 soluble plasma fibronectin_(formerly_called "cold-insoluble globulin",_or CIg) is a major protein component of blood_plasma (300 μg/ml) and is produced_in the liver_by_hepatocytes.
_insoluble cellular fibronectin is_a major component of the extracellular_matrix. It is secreted by various_cells, primarily fibroblasts, as a soluble protein_dimer and is then assembled into_an insoluble matrix in a_complex cell-mediated_process.

Fibronectin plays a major role_in cell adhesion,_growth, migration,_and differentiation, and_it is important for processes such_as wound healing_and embryonic development.  Altered fibronectin_expression,_degradation, and organization_has_been_associated with_a number of_pathologies,_including cancer_and_fibrosis.

Structure 
Fibronectin exists as a protein_dimer,_consisting of two nearly identical polypeptide chains_linked by a pair_of_C-terminal disulfide bonds. _Each fibronectin subunit has a_molecular weight of 230–250 kDa and_contains three_types of_modules: type I, II, and III.  All three modules are_composed of two anti-parallel β-sheets resulting_in a Beta-sandwich; however,_type I_and_type II are_stabilized_by intra-chain_disulfide bonds, while type III modules do_not contain_any disulfide bonds. The absence of_disulfide bonds in type_III_modules allows them to partially unfold_under applied force.

Three regions of variable_splicing occur along the length_of_the_fibronectin protomer.  One or_both of the "extra" type III_modules (EIIIA and_EIIIB) may be present in cellular fibronectin,_but_they are never present in plasma_fibronectin._ A "variable" V-region exists between_III14–15_(the_14th and 15th type III_module).  The V-region structure is_different from the type I, II, and III modules,_and its presence_and length may vary. _The_V-region_contains the binding site for α4β1 integrins.  It is_present in_most cellular fibronectin,_but only one of the