Proteomic Analysis of Col11a1-associated Protein Complexes

Cartilage plays an essential role during skeletal development within the growth plate and in articular joint function. Interactions between the collagen fibrils and other extracellular matrix molecules maintain structural integrity of cartilage, orchestrate complex dynamic events during embryonic development, and help to regulate fibrillogenesis. To increase our understanding of these events, affinity chromatography and liquid chromatography/tandem mass spectrometry were used to identify proteins that interact with the collagen fibril surface via the amino terminal domain of collagen alpha 1(XI) a protein domain that is displayed at the surface of heterotypic collagen fibrils of cartilage. Proteins extracted from fetal bovine cartilage using homogenization in high ionic strength buffer were selected based on affinity for the amino terminal noncollagenous domain of collagen alpha 1(XI). Mass spectrometry was used to determine the amino acid sequence of tryptic fragments for protein identification. Extracellular matrix molecules and cellular proteins that were identified as interacting with the amino terminal domain of collagen alpha 1(XI) directly or indirectly, included proteoglycans, collagens, and matricellular molecules, some of which also play a role in fibrillogenesis, while others are known to function in the maintenance of tissue integrity. Characterization of these molecular interactions will provide a more thorough understanding of how the extracellular matrix molecules of cartilage interact and what role collagen XI plays in the process of fibrillogenesis and maintenance of tissue integrity. Such information will aid tissue engineering and cartilage regeneration efforts to treat cartilage tissue damage and degeneratio

Bare coordination: the semantic shift

This paper develops an analysis of the syntax-semantics interface of two types of split coordination structures. In the first type, two bare singular count nouns appear as arguments in a coordinated structure, as in bride and groom were happy. We call this the N&N construction. In the second type, the determiner shows agreement with the first conjunct, while the second conjunct is bare, as in the Spanish example el hornero y hornera cobraban en panes (‘thesg.m bakersg.m and bakersg.f werepl paid in bread loaves’). We call this the DN&N construction. Both N&N and DN&N constructions are common in languages that otherwise require an article or determiner on singular count nouns in regular argument position, and give rise to ‘split’ readings that cannot be accounted for by the standard semantics of conjunction in terms of set intersection. Furthermore, they are restricted to instances of ‘natural’ coordination. We formalize the semantics of split conjunction in terms of intersection between sets of matching pairs, which correlates with the lexical semantics and pragmatics of natural coordination. We maintain that an N&N construction gets either a definite or an indefinite interpretation by covert type-shifting, because projection of an article ranging over the coordination as a whole is blocked in languages like English and Spanish. For DN&N structures, we propose a syntactic structure in which D is in construction with the first conjunct. Coordination with a second, bare conjunct requires a covert type-shift that is licensed only under the special matchmaking semantics of conjunction. The analysis addresses a range of issues these coordinate structures raise about syntactic and semantic agreement, in particular with respect to number. Next to English and Spanish we will look into Dutch and French in detail